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Encyclopedia > Laser
Experiment with a laser (U.S. Air Force)
Experiment with a laser (U.S. Air Force)

A laser is an electronic-optical device that emits coherent light radiation. The term "laser" is an acronym for Light Amplification by Stimulated Emission of Radiation.[1][2] A typical laser emits light in a narrow, low-divergence monochromatic (single-coloured, if the laser is operating in the visible spectrum), beam with a well-defined wavelength. In this respect, laser light is in sharp contrast with such light sources as the incandescent light bulb, which emits light over a wide area and over a wide spectrum of wavelengths. Generally, a Laser is a device which uses a quantum mechanical effect, stimulated emission, to generate a coherent beam of light. ... Image File history File links Download high resolution version (3008x1960, 1023 KB) Summary Very likely an argon ion laser. ... Image File history File links Download high resolution version (3008x1960, 1023 KB) Summary Very likely an argon ion laser. ... Seal of the Air Force. ... Coherence is the property of wave-like states that enables them to exhibit interference. ... For other uses, see Radiation (disambiguation). ... It has been suggested that this article or section be merged with Backronym and Apronym (Discuss) Acronyms and initialisms are abbreviations, such as NATO, laser, and ABC, written as the initial letter or letters of words, and pronounced on the basis of this abbreviated written form. ... The beam divergence of an electromagnetic beam is the increase in beam diameter with distance from the aperture from which the beam emerges in any plane that intersects the beam axis. ... Visible light redirects here. ... For other uses, see Wavelength (disambiguation). ... Prism splitting light Light is electromagnetic radiation with a wavelength that is visible to the eye, or in a more general sense, any electromagnetic radiation in the range from infrared to ultraviolet. ... Light bulb redirects here. ... Although some radiations are marked as N for no in the diagram, some waves do in fact penetrate the atmosphere, although extremely minimally compared to the other radiations The electromagnetic (EM) spectrum is the range of all possible electromagnetic radiation. ...


The first working laser was demonstrated on May 16, 1960 by Theodore Maiman at Hughes Research Laboratories.[3] Since then, lasers have become a multi-billion dollar industry. The most widespread[citation needed] use of lasers is in optical storage devices such as compact disc and DVD players, in which the laser (a few millimeters in size) scans the surface of the disc. Other common applications of lasers are bar code readers, laser printers and laser pointers. is the 136th day of the year (137th in leap years) in the Gregorian calendar. ... Year 1960 (MCMLX) was a leap year starting on Friday (link will display full calendar) of the Gregorian calendar. ... Theodore Maiman. ... In the 1940s, Howard Hughes created a R&D facility in Culver City, California; by the early 1960s, it had been moved to Malibu, California. ... Optical Storage is made possible by data storage devices such as optical discs and holographic storage systems. ... CD redirects here. ... DVD (also known as Digital Versatile Disc or Digital Video Disc - see Etymology) is a popular optical disc storage media format. ... Wikipedia encoded in Code 128_B A barcode (also bar code) is a machine-readable representation of information in a visual format on a surface. ... A laser printer is a common type of computer printer that produces good quality printing, and is able to produce text and graphics. ... A keychain laser pointer. ...


In industry, lasers are used for cutting steel and other metals and for inscribing patterns (such as the letters on computer keyboards). Lasers are also commonly used in various fields in science, especially spectroscopy, typically because of their well-defined wavelength or short pulse duration in the case of pulsed lasers. Lasers are used by the military for rangefinding, target identification and illumination for weapons delivery. Lasers used in medicine are used for internal surgery and cosmetic applications. Laser cutting is a technology which uses a laser to cut materials, and is usually used in industrial manufacturing. ... A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... Animation of the dispersion of light as it travels through a triangular prism. ...

Contents

Design

Principal components:1. Gain medium2. Laser pumping energy3. High reflector4. Output coupler5. Laser beam
Principal components:
1. Gain medium
2. Laser pumping energy
3. High reflector
4. Output coupler
5. Laser beam
Main article: Laser construction

A laser consists of a gain medium inside a highly reflective optical cavity, as well as a means to supply energy to the gain medium. The gain medium is a material with properties that allow it to amplify light by stimulated emission. In its simplest form, a cavity consists of two mirrors arranged such that light bounces back and forth, each time passing through the gain medium. Typically one of the two mirrors, the output coupler, is partially transparent. The output laser beam is emitted through this mirror. Image File history File links Laser. ... Image File history File links Laser. ... Principal components of a laser: 1. ... A laser system generally consists of three important parts: An energy source (usually referred to as the pump or pump source); A gain medium or laser medium; A mirror, or system of mirrors, forming an optical resonator. ... The active laser medium or gain medium is the material that exhibits optical gain within a laser. ... A cavity resonator uses resonance to amplify a wave. ... In optics, stimulated emission is the process by which, when perturbed by a photon, matter may lose energy resulting in the creation of another photon. ... Principal components of a laser: 1. ...


Light of a specific wavelength that passes through the gain medium is amplified (increases in power); the surrounding mirrors ensure that most of the light makes many passes through the gain medium, being amplified repeatedly. Part of the light that is between the mirrors (that is, within the cavity) passes through the partially transparent mirror and escapes as a beam of light. An optical amplifier is a device that amplifies an optical signal directly, without the need to first convert it to an electrical signal. ...


The process of supplying the energy required for the amplification is called pumping. The energy is typically supplied as an electrical current or as light at a different wavelength. Such light may be provided by a flash lamp or perhaps another laser. Most practical lasers contain additional elements that affect properties such as the wavelength of the emitted light and the shape of the beam. Laser pumping is the act of energy transfer from an external source into the laser gain medium. ... U-shaped Xenon Flash Lamp A xenon flash lamp is a gas discharge lamp designed to produce extremely intense, incoherent, full-spectrum white light for very short durations. ...


Terminology

The word light in the acronym Light Amplification by Stimulated Emission of Radiation is typically used in the broader sense, as including photons of any electromagnetic energy, not just those in the visible spectrum. Hence there are infrared lasers, ultraviolet lasers, X-ray lasers, etc. Because the microwave equivalent of the laser, the maser, was developed first, devices that emit microwave and radio frequencies are usually called masers. In early literature, particularly from researchers at Bell Telephone Laboratories, the laser was often called the optical maser. This usage has since become uncommon, and as of 1998 even Bell Labs uses the term laser.[4] Image File history File links Spectre. ... Image File history File links Spectre. ... This article is about electromagnetic radiation. ... An X-ray picture (radiograph), taken by Wilhelm Röntgen in 1896, of his wife, Anna Bertha Ludwigs[1] hand X-rays (or Röntgen rays) are a form of electromagnetic radiation with a wavelength in the range of 10 to 0. ... For other uses, see Ultraviolet (disambiguation). ... Visible light redirects here. ... For other uses, see Infrared (disambiguation). ... Microwave Slang for small waves, like at a beach, often used by surfers. ... Radio waves are electromagnetic waves occurring on the radio frequency portion of the electromagnetic spectrum. ... In modern physics the photon is the elementary particle responsible for electromagnetic phenomena. ... Visible light redirects here. ... For other uses, see Infrared (disambiguation). ... For other uses, see Ultraviolet (disambiguation). ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... This article is about the type of Electromagnetic radiation. ... A hydrogen radio frequency discharge, the first element inside a hydrogen maser (see description below) A maser is a device that produces coherent electromagnetic waves through amplification due to stimulated emission. ... Bell Telephone Laboratories or Bell Labs was originally the research and development arm of the United States Bell System, and was the premier corporate facility of its type, developing a range of revolutionary technologies from telephone switches to specialized coverings for telephone cables, to the transistor. ...


The back-formed verb to lase means "to produce laser light" or "to apply laser light to".[5] The word "laser" is sometimes used to describe other non-light technologies. For example, a source of atoms in a coherent state is called an "atom laser". In etymology, the process of back-formation is the creation of a neologism by reinterpreting an earlier word as a compound and removing the spuriously supposed affixes. ... An atom laser is a coherent state of propagating atoms. ...


Laser physics

A helium-neon laser demonstration at the Kastler-Brossel Laboratory at Univ. Paris 6. The glowing ray in the middle is an electric discharge producing light in much the same way as a neon light. It is the gain medium through which the laser passes, not the laser beam itself, which is visible there. The laser beam crosses the air and marks a red point on the screen to the right.
A helium-neon laser demonstration at the Kastler-Brossel Laboratory at Univ. Paris 6. The glowing ray in the middle is an electric discharge producing light in much the same way as a neon light. It is the gain medium through which the laser passes, not the laser beam itself, which is visible there. The laser beam crosses the air and marks a red point on the screen to the right.
Spectrum of a helium neon laser showing the very high spectral purity intrinsic to nearly all lasers. Compare with the relatively broad spectral emittance of a light emitting diode.
See also: Laser science

The gain medium of a laser is a material of controlled purity, size, concentration, and shape, which amplifies the beam by the process of stimulated emission. It can be of any state: gas, liquid, solid or plasma. The gain medium absorbs pump energy, which raises some electrons into higher-energy ("excited") quantum states. Particles can interact with light both by absorbing photons or by emitting photons. Emission can be spontaneous or stimulated. In the latter case, the photon is emitted in the same direction as the light that is passing by. When the number of particles in one excited state exceeds the number of particles in some lower-energy state, population inversion is achieved and the amount of stimulated emission due to light that passes through is larger than the amount of absorption. Hence, the light is amplified. By itself, this makes an optical amplifier. When an optical amplifier is placed inside a resonant optical cavity, one obtains a laser. Download high resolution version (1716x1692, 350 KB)Helium-Neon laser demonstration at the Kastler-Brossel Laboratory at Paris VI: Pierre et Marie Curie. ... Download high resolution version (1716x1692, 350 KB)Helium-Neon laser demonstration at the Kastler-Brossel Laboratory at Paris VI: Pierre et Marie Curie. ... A helium-neon laser, usually called a HeNe laser, is a type of small gas laser. ... The University of Paris VI: Pierre et Marie Curie is a French university, principal inheritor of the Faculty of Sciences of the University of Paris. ... The active laser medium or gain medium is the material that exhibits optical gain within a laser. ... Image File history File links Download high resolution version (2748x1870, 104 KB) Summary Spectrum of a Helium neon laser taken using an Ocean Optics HR4000 spectrometer [1] by bouncing the laser off of a white benchtop and guiding the diffuse reflected light directly into the spectrometer. ... Image File history File links Download high resolution version (2748x1870, 104 KB) Summary Spectrum of a Helium neon laser taken using an Ocean Optics HR4000 spectrometer [1] by bouncing the laser off of a white benchtop and guiding the diffuse reflected light directly into the spectrometer. ... Image File history File links Download high-resolution version (1073x758, 20 KB) Combined spectra of a common blue LED, a yellow-green LED and a high brightness red LED from the bottom of a microsoft optical mouse. ... Laser science is a branch of optics that describes the theory and practice of lasers. ... A State of matter is a class of materials, for example solid, liquid, or gas, also called a physical state or phase. ... For other uses, see Gas (disambiguation). ... For other uses, see Liquid (disambiguation). ... This box:      For other uses, see Solid (disambiguation). ... For other uses, see Plasma. ... After absorbing energy, an electron may jump from the ground state to a higher energy excited state. ... Probability densities for the electron at different quantum numbers (l) In quantum mechanics, the quantum state of a system is a set of numbers that fully describe a quantum system. ... In physics, specifically statistical mechanics, the concept of population inversion is of fundamental importance in laser science because the production of a population inversion is a necessary step in the workings of a laser. ... An optical amplifier is a device that amplifies an optical signal directly, without the need to first convert it to an electrical signal. ...


The light generated by stimulated emission is very similar to the input signal in terms of wavelength, phase, and polarization. This gives laser light its characteristic coherence, and allows it to maintain the uniform polarization and often monochromaticity established by the optical cavity design. This article is about a portion of a periodic process. ...


The optical cavity, a type of cavity resonator, contains a coherent beam of light between reflective surfaces so that the light passes through the gain medium more than once before it is emitted from the output aperture or lost to diffraction or absorption. As light circulates through the cavity, passing through the gain medium, if the gain (amplification) in the medium is stronger than the resonator losses, the power of the circulating light can rise exponentially. But each stimulated emission event returns a particle from its excited state to the ground state, reducing the capacity of the gain medium for further amplification. When this effect becomes strong, the gain is said to be saturated. The balance of pump power against gain saturation and cavity losses produces an equilibrium value of the laser power inside the cavity; this equilibrium determines the operating point of the laser. If the chosen pump power is too small, the gain is not sufficient to overcome the resonator losses, and the laser will emit only very small light powers. The minimum pump power needed to begin laser action is called the lasing threshold. The gain medium will amplify any photons passing through it, regardless of direction; but only the photons aligned with the cavity manage to pass more than once through the medium and so have significant amplification. To meet Wikipedias quality standards, this article or section may require cleanup. ... In mathematics, exponential growth (or geometric growth) occurs when the growth rate of a function is always proportional to the functions current size. ... In a laser, the lasing threshold is the lowest excitation level at which the lasers output is dominated by stimulated emission rather than by spontaneous emission. ...


The beam in the cavity and the output beam of the laser, if they occur in free space rather than waveguides (as in an optical fiber laser), are, at best, low order Gaussian beams. However this is rarely the case with powerful lasers. If the beam is not a low-order Gaussian shape, the transverse modes of the beam can be described as a superposition of Hermite-Gaussian or Laguerre-Gaussian beams (for stable-cavity lasers). Unstable laser resonators on the other hand, have been shown to produce fractal shaped beams.[6] The beam may be highly collimated, that is being parallel without diverging. However, a perfectly collimated beam cannot be created, due to diffraction. The beam remains collimated over a distance which varies with the square of the beam diameter, and eventually diverges at an angle which varies inversely with the beam diameter. Thus, a beam generated by a small laboratory laser such as a helium-neon laser spreads to about 1.6 kilometers (1 mile) diameter if shone from the Earth to the Moon. By comparison, the output of a typical semiconductor laser, due to its small diameter, diverges almost as soon as it leaves the aperture, at an angle of anything up to 50°. However, such a divergent beam can be transformed into a collimated beam by means of a lens. In contrast, the light from non-laser light sources cannot be collimated by optics as well. Optical fibers An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length. ... In optics, a Gaussian beam is a beam of electromagnetic radiation whose transverse electric field and intensity (irradiance) distributions are described by Gaussian functions. ... A transverse mode of a beam of electromagnetic radiation is a particular intensity pattern of radiation measured in a plane perpendicular (i. ... In mathematics, the Hermite polynomials are a classical orthogonal polynomial sequence that arise in probability, such as the Edgeworth series; in combinatorics, as an example of an Appell sequence, obeying the umbral calculus; and in physics, as the eigenstates of the quantum harmonic oscillator. ... Gaussian curves parametrised by expected value and variance (see normal distribution) In mathematics, a Gaussian function (named after Carl Friedrich Gauss) is a function of the form: for some real constants a > 0, b, and c. ... In mathematics, the Laguerre polynomials, named after Edmond Laguerre (1834 - 1886), are a polynomial sequence defined by These polynomials are orthogonal to each other with respect to the inner product given by Also, for each n, Ln(x) is a solution of Laguerres equation which is a second-order... Collimated light is light whose rays are parallel. ... The beam divergence of an electromagnetic beam is the increase in beam diameter with distance from the aperture from which the beam emerges in any plane that intersects the beam axis. ... The intensity pattern formed on a screen by diffraction from a square aperture Diffraction refers to various phenomena associated with wave propagation, such as the bending, spreading and interference of waves passing by an object or aperture that disrupts the wave. ... A helium-neon laser, usually called a HeNe laser, is a type of small gas laser. ... This article is about Earth as a planet. ... This article is about Earths moon. ... This article is about the optical device. ...


Although the laser phenomenon was discovered with the help of quantum physics, it is not essentially more quantum mechanical than other light sources. The operation of a free electron laser can be explained without reference to quantum mechanics. Fig. ... X-ray free electronic laser schema of operation A free electron laser, or FEL, is a laser that shares the same optical properties as conventional lasers such as emitting a beam consisting of coherent electromagnetic radiation which can reach high power, but which uses some very different operating principles to... For a generally accessible and less technical introduction to the topic, see Introduction to quantum mechanics. ...


Modes of operation

The output of a laser may be a continuous constant-amplitude output (known as CW or continuous wave); or pulsed, by using the techniques of Q-switching, modelocking, or gain-switching. In pulsed operation, much higher peak powers can be achieved. A continuous wave (CW) is an electromagnetic wave of constant amplitude and frequency. ... Q-switching, sometimes known as giant pulse formation, is a technique discovered circa 1962 by R.W. Hellwarth and F.J. McClung using electrically switched Kerr cell shutters and is a technique by which a laser can be made to produce a pulsed output beam. ... Mode-locking is a technique in optics by which a laser can be made to produce pulses of light of extremely short duration, on the order of picoseconds (10-12s) or femtoseconds (10-15s). ... Gain-switching is a technique in optics by which a laser can be made to produce pulses of light of extremely short duration, of the order of picoseconds (10-12s). ...


Some types of lasers, such as dye lasers and vibronic solid-state lasers can produce light over a broad range of wavelengths; this property makes them suitable for generating extremely short pulses of light, on the order of a few femtoseconds (10-15 s). To help compare orders of magnitude of different times this page lists times between 10−15 seconds and 10−12 seconds (1 femtosecond and 1 picosecond). ...


Continuous wave operation

In the continuous wave (CW) mode of operation, the output of a laser is relatively consistent with respect to time. The population inversion required for lasing is continually maintained by a steady pump source. A continuous wave (CW) is an electromagnetic wave of constant amplitude and frequency. ...


Pulsed operation

In the pulsed mode of operation, the output of a laser varies with respect to time, typically taking the form of alternating 'on' and 'off' periods. In many applications one aims to deposit as much energy as possible at a given place in as short time as possible. In laser ablation for example, a small volume of material at the surface of a work piece might evaporate if it gets the energy required to heat it up far enough in very short time. If, however, the same energy is spread over a longer time, the heat may have time to disperse into the bulk of the piece, and less material evaporates. There are a number of methods to achieve this. Guo et al. ... Disperse is a Christian Rock band from Southern Indiana. ...


Q-switching
Main article: Q-switching

In a Q-switched laser, the population inversion (usually produced in the same way as CW operation) is allowed to build up by making the cavity conditions (the 'Q') unfavorable for lasing. Then, when the pump energy stored in the laser medium is at the desired level, the 'Q' is adjusted (electro- or acousto-optically) to favorable conditions, releasing the pulse. This results in high peak powers as the average power of the laser (were it running in CW mode) is packed into a shorter time frame. Q-switching, sometimes known as giant pulse formation, is a technique discovered circa 1962 by R.W. Hellwarth and F.J. McClung using electrically switched Kerr cell shutters and is a technique by which a laser can be made to produce a pulsed output beam. ...


Modelocking
Main article: Modelocking

A modelocked laser emits extremely short pulses on the order of tens of picoseconds down to less than 10 femtoseconds. These pulses are typically separated by the time that a pulse takes to complete one round trip in the resonator cavity. Due to the Fourier limit (also known as energy-time uncertainty), a pulse of such short temporal length has a spectrum which contains a wide range of wavelengths. Because of this, the laser medium must have a broad enough gain profile to amplify them all. An example of a suitable material is titanium-doped, artificially grown sapphire (Ti:sapphire). Mode-locking is a technique in optics by which a laser can be made to produce pulses of light of extremely short duration, on the order of picoseconds (10-12s) or femtoseconds (10-15s). ... A picosecond is an SI unit of time equal to 10-12 of a second. ... A femtosecond is the SI unit of time equal to 10-15 of a second. ... In mathematics, the Fourier transform is a certain linear operator that maps functions to other functions. ... In quantum physics, the outcome of even an ideal measurement of a system is not deterministic, but instead is characterized by a probability distribution, and the larger the associated standard deviation is, the more uncertain we might say that that characteristic is for the system. ... General Name, symbol, number titanium, Ti, 22 Chemical series transition metals Group, period, block 4, 4, d Appearance silvery grey-white metallic Standard atomic weight 47. ... For other uses, see Sapphire (disambiguation). ... Part of a Ti:sapphire oscillator. ...


The modelocked laser is a most versatile tool for researching processes happening at extremely fast time scales also known as femtosecond physics, femtosecond chemistry and ultrafast science, for maximizing the effect of nonlinearity in optical materials (e.g. in second-harmonic generation, parametric down-conversion, optical parametric oscillators and the like), and in ablation applications. Again, because of the short timescales involved, these lasers can achieve extremely high powers. Femtochemistry is the science that studies chemical reactions on extremely short timescales, approximately 10–15 seconds (this is one femtosecond, hence the name). ... It has been suggested that this article or section be merged into Ultrashort pulse. ... Nonlinear optics is the branch of optics that describes the behaviour of light in nonlinear media, that is, media in which the polarization P responds nonlinearly to the electric field E of the light. ... Second harmonic generation (SHG; also called frequency doubling) is a nonlinear optical process, in which photons interacting with a nonlinear material are effectively combined to form new photons with twice the energy, and therefore twice the frequency and half the wavelength of the initial photons. ... Parametric down-conversion is an important process in quantum optics. ... An optical parametric oscillator (OPO) converts a input laser wave (called pump) into two output waves of lower frequency () by means of nonlinear optical interaction. ...


Pulsed pumping

Another method of achieving pulsed laser operation is to pump the laser material with a source that is itself pulsed, either through electronic charging in the case of flashlamps, or another laser which is already pulsed. Pulsed pumping was historically used with dye lasers where the inverted population lifetime of a dye molecule was so short that a high energy, fast pump was needed. The way to overcome this problem was to charge up large capacitors which are then switched to discharge through flashlamps, producing a broad spectrum pump flash. Pulsed pumping is also required for lasers which disrupt the gain medium so much during the laser process that lasing has to cease for a short period. These lasers, such as the excimer laser and the copper vapour laser, can never be operated in CW mode.


History

Foundations

In 1917 Albert Einstein, in his paper Zur Quantentheorie der Strahlung (On the Quantum Theory of Radiation), laid the foundation for the invention of the laser and its predecessor, the maser, in a ground-breaking rederivation of Max Planck's law of radiation based on the concepts of probability coefficients (later to be termed 'Einstein coefficients') for the absorption, spontaneous, and stimulated emission. “Einstein” redirects here. ... A hydrogen radio frequency discharge, the first element inside a hydrogen maser (see description below) A maser is a device that produces coherent electromagnetic waves through amplification due to stimulated emission. ... Planck redirects here. ...


In 1928, Rudolph W. Landenburg confirmed the existence of stimulated emission and negative absorption.[7] In 1939, Valentin A. Fabrikant (USSR) predicted the use of stimulated emission to amplify "short" waves.[8]


In 1947, Willis E. Lamb and R. C. Retherford found apparent stimulated emission in hydrogen spectra and made the first demonstration of stimulated emission.[9] Willis Eugene Lamb, Junior (b. ...


In 1950, Alfred Kastler (Nobel Prize for Physics 1966) proposed the method of optical pumping, which was experimentally confirmed by Brossel, Kastler and Winter two years later.[10] Alfred Kastler (May 3, 1902 - January 7, 1984) is a French physicist, born in Guebwiller, who won the Nobel Prize for Physics in 1966. ...


Maser

In 1953, Charles H. Townes and graduate students James P. Gordon and Herbert J. Zeiger produced the first microwave amplifier, a device operating on similar principles to the laser, but amplifying microwave rather than infrared or visible radiation. Townes's maser was incapable of continuous output. Nikolay Basov and Aleksandr Prokhorov of the Soviet Union worked independently on the quantum oscillator and solved the problem of continuous output systems by using more than two energy levels and produced the first maser. These systems could release stimulated emission without falling to the ground state, thus maintaining a population inversion. In 1955 Prokhorov and Basov suggested an optical pumping of multilevel system as a method for obtaining the population inversion, which later became one of the main methods of laser pumping. Charles Hard Townes (born July 28, 1915) is an American Nobel Prize-winning physicist and educator. ... This article is about the type of Electromagnetic radiation. ... For other uses, see Infrared (disambiguation). ... A hydrogen radio frequency discharge, the first element inside a hydrogen maser (see description below) A maser is a device that produces coherent electromagnetic waves through amplification due to stimulated emission. ... Nikolay Gennadiyevich Basov (Russian:Николай Геннадиевич Басов) (December 14, 1922 – July 1, 2001) was a Soviet/Russian physicist and educator. ... Aleksandr Mikhailovich Prokhorov (Russian: Александр Михайлович Прохоров) (July 11, 1916 – January 8, 2002) was an Australian-Russian physicist. ... Oscillation is the variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. ... In optics, stimulated emission is the process by which, when perturbed by a photon, matter may lose energy resulting in the creation of another photon. ... In physics, specifically statistical mechanics, the concept of population inversion is of fundamental importance in laser science because the production of a population inversion is a necessary step in the workings of a laser. ...


Townes reports that he encountered opposition from a number of eminent colleagues who thought the maser was theoretically impossible -- including Niels Bohr, John von Neumann, Isidor Rabi, Polykarp Kusch, and Llewellyn H. Thomas[1]. Niels Henrik David Bohr (October 7, 1885 – November 18, 1962) was a Danish physicist who made fundamental contributions to understanding atomic structure and quantum mechanics, for which he received the Nobel Prize in Physics in 1922. ... For other persons named John Neumann, see John Neumann (disambiguation). ... Isidor Isaac Rabi (July 29, 1898 - January 11, 1988) was an American physicist of Austro-Hungarian origin. ... Polykarp Kusch (January 26, 1911 - March 20, 1993) was a German-American physicist who, with Willis Eugene Lamb, was awarded the Nobel Prize for Physics in 1955 for his accurate determination that the magnetic moment of the electron was greater than its theoretical value, thus leading to reconsideration of and...


Townes, Basov, and Prokhorov shared the Nobel Prize in Physics in 1964 "For fundamental work in the field of quantum electronics, which has led to the construction of oscillators and amplifiers based on the maser-laser principle". Hannes Alfvén (1908–1995) accepting the Nobel Prize for his work on magnetohydrodynamics [1]. List of Nobel Prize laureates in Physics from 1901 to the present day. ...


Laser

In 1957, Charles Hard Townes and Arthur Leonard Schawlow, then at Bell Labs, began a serious study of the infrared laser. As ideas were developed, infrared frequencies were abandoned with focus on visible light instead. The concept was originally known as an "optical maser". Bell Labs filed a patent application for their proposed optical maser a year later. Schawlow and Townes sent a manuscript of their theoretical calculations to Physical Review, which published their paper that year (Volume 112, Issue 6). Arthur Leonard Schawlow (May 5, 1921 – April 28, 1999) was an American physicist. ... Bell Laboratories (also known as Bell Labs and formerly known as AT&T Bell Laboratories and Bell Telephone Laboratories) was the main research and development arm of the United States Bell System. ... For other uses, see Infrared (disambiguation). ... The optical spectrum (light or visible spectrum) is the portion of the electromagnetic spectrum that is visible to the human eye. ... For other uses, see Patent (disambiguation). ... Physical Review is one of the oldest and most-respected scientific journals publishing research on all aspects of physics. ...

The first page of Gordon Gould's laser notebook in which he coined the acronym LASER and described the essential elements for constructing one.
The first page of Gordon Gould's laser notebook in which he coined the acronym LASER and described the essential elements for constructing one.

At the same time Gordon Gould, a graduate student at Columbia University, was working on a doctoral thesis on the energy levels of excited thallium. Gould and Townes met and had conversations on the general subject of radiation emission. Afterwards Gould made notes about his ideas for a "laser" in November 1957, including suggesting using an open resonator, which became an important ingredient of future lasers. Image File history File links Download high-resolution version (767x1023, 307 KB)This is the first page of Gordon Goulds famous notebook, in which he coined the acronym LASER, and described the essential elements for constructing one. ... Image File history File links Download high-resolution version (767x1023, 307 KB)This is the first page of Gordon Goulds famous notebook, in which he coined the acronym LASER, and described the essential elements for constructing one. ... The first page of Gordon Goulds famous notebook, in which he coined the acronym LASER and described the essential elements for constructing one. ... Alma Mater Columbia University is a private university in the United States and a member of the Ivy League. ... Doctor of Philosophy (Ph. ... General Name, Symbol, Number thallium, Tl, 81 Chemical series poor metals Group, Period, Block 13, 6, p Appearance silvery white Standard atomic weight 204. ... In physics, emission is the process by which the energy of a photon is released by another entity, for example, by an atom whose valence electrons make a transition between two electronic energy levels. ... A resonator is a device or part that vibrates (or oscillates) with waves. ...


In 1958, Prokhorov independently proposed using an open resonator, the first published appearance of this idea. Schawlow and Townes also settled on an open resonator design, apparently unaware of both the published work of Prokhorov and the unpublished work of Gould.


The term "laser" was first introduced to the public in Gould's 1959 conference paper "The LASER, Light Amplification by Stimulated Emission of Radiation".[1][11] Gould intended "-aser" to be a suffix, to be used with an appropriate prefix for the spectra of light emitted by the device (x-ray laser = xaser, ultraviolet laser = uvaser, etc.). None of the other terms became popular, although "raser" was used for a short time to describe radio-frequency emitting devices.


Gould's notes included possible applications for a laser, such as spectrometry, interferometry, radar, and nuclear fusion. He continued working on his idea and filed a patent application in April 1959. The U.S. Patent Office denied his application and awarded a patent to Bell Labs in 1960. This sparked a legal battle that ran 28 years, with scientific prestige and much money at stake. Gould won his first minor patent in 1977, but it was not until 1987 that he could claim his first significant patent victory when a federal judge ordered the government to issue patents to him for the optically pumped laser and the gas discharge laser. Animation of the dispersion of light as it travels through a triangular prism. ... It has been suggested that Optical interferometry be merged into this article or section. ... For other uses, see Radar (disambiguation). ... The deuterium-tritium (D-T) fusion reaction is considered the most promising for producing sustainable fusion power. ... A patent application is a request pending at a patent office for the grant of a patent for the invention described and claimed by that application. ... PTO headquarters in Alexandria The United States Patent and Trademark Office (PTO or USPTO) is an agency in the United States Department of Commerce that provides patent and trademark protection to inventors and businesses for their inventions and corporate and product identification. ... Bell Laboratories (also known as Bell Labs and formerly known as AT&T Bell Laboratories and Bell Telephone Laboratories) was the main research and development arm of the United States Bell System. ... -1...


The first working laser was made by Theodore H. Maiman in 1960[12] at Hughes Research Laboratories in Malibu, California, beating several research teams including those of Townes at Columbia University, Arthur L. Schawlow at Bell Labs,[13] and Gould at a company called TRG (Technical Research Group). Maiman used a solid-state flashlamp-pumped synthetic ruby crystal to produce red laser light at 694 nanometres wavelength. Maiman's laser, however, was only capable of pulsed operation due to its three energy level pumping scheme. Theodore Maiman. ... In the 1940s, Howard Hughes created a R&D facility in Culver City, California; by the early 1960s, it had been moved to Malibu, California. ... Location of Malibu in Los Angeles County, California Coordinates: , Country State County Los Angeles Incorporated (city) 1991-03-28 [2] Government  - Mayor Jeff Jennings [1] Area  - Total 100. ... Charles Hard Townes (born July 28, American physicist and educator. ... Alma Mater Columbia University is a private university in the United States and a member of the Ivy League. ... U-shaped Xenon Flash Lamp A xenon flash lamp is a gas discharge lamp designed to produce extremely intense, incoherent, full-spectrum white light for very short durations. ... This article is about the mineral. ... For other uses, see Crystal (disambiguation). ...


Later in 1960 the Iranian physicist Ali Javan, working with William R. Bennett and Donald Herriot, made the first gas laser using helium and neon. Javan later received the Albert Einstein Award in 1993. Ali Javan (Persian: علی جوان , born 1928 in Tehran, Iran) is an Iranian inventor and physicist at MIT. He invented the gas laser in 1960. ... For other persons of the same name, see William Bennett (disambiguation). ... The gas laser is a kind of laser in which some sort of gas (such as helium or neon) is discharged to produce the laser light. ... General Name, symbol, number helium, He, 2 Chemical series noble gases Group, period, block 18, 1, s Appearance colorless Standard atomic weight 4. ... For other uses, see Neon (disambiguation). ... The Albert Einstein Award (sometimes called the Albert Einstein Medal because it is accompanied with a gold medal) is an award in theoretical physics, that was established to recognize high achievement in the natural sciences. ...


The concept of the semiconductor laser diode was proposed by Basov and Javan. The first laser diode was demonstrated by Robert N. Hall in 1962. Hall's device was made of gallium arsenide and emitted at 850 nm in the near-infrared region of the spectrum. The first semiconductor laser with visible emission was demonstrated later the same year by Nick Holonyak, Jr. As with the first gas lasers, these early semiconductor lasers could be used only in pulsed operation, and indeed only when cooled to liquid nitrogen temperatures (77 K). A packaged laser diode with penny for scale. ... American inventor Robert N. Hall (December 25, 1919-) demonstrated the first semiconductor laser, and invented a type of magnetron commonly used in microwave ovens. ... This article is about the chemical compound. ... For other uses, see Infrared (disambiguation). ... Nick Holonyak Jr. ... A tank of liquid nitrogen, used to supply a cryogenic freezer (for storing laboratory samples at a temperature of about -150 Celsius). ...


In 1970, Zhores Alferov in the Soviet Union and Izuo Hayashi and Morton Panish of Bell Telephone Laboratories independently developed laser diodes continuously operating at room temperature, using the heterojunction structure. Zhores Ivanovich Alferov Zhores Ivanovich Alferov (also Alfyorov) (Russian: Жоре́с Ива́нович Алфёров) (born March 15, 1930) is a Russian physicist who contributed significantly to the creation of modern heterostructure physics and electronics. ... Bell Telephone Laboratories or Bell Labs was originally the research and development arm of the United States Bell System, and was the premier corporate facility of its type, developing a range of revolutionary technologies from telephone switches to specialized coverings for telephone cables, to the transistor. ... A heterojunction is a semiconductor diode junction which is composed of alternating layers of semiconductor material. ...


Recent innovations

Graph showing the history of maximum laser pulse intensity throughout the past 40 years.
Graph showing the history of maximum laser pulse intensity throughout the past 40 years.

Since the early period of laser history, laser research has produced a variety of improved and specialized laser types, optimized for different performance goals, including: Image File history File links History_of_laser_intensity. ... Image File history File links History_of_laser_intensity. ...

  • new wavelength bands
  • maximum average output power
  • maximum peak output power
  • minimum output pulse duration
  • maximum power efficiency
  • maximum charging
  • maximum firing

and this research continues to this day.


Lasing without maintaining the medium excited into a population inversion, was discovered in 1992 in sodium gas and again in 1995 in rubidium gas by various international teams. This was accomplished by using an external maser to induce "optical transparency" in the medium by introducing and destructively interfering the ground electron transitions between two paths, so that the likelihood for the ground electrons to absorb any energy has been cancelled. For sodium in the diet, see Salt. ... General Name, Symbol, Number rubidium, Rb, 37 Chemical series alkali metals Group, Period, Block 1, 5, s Appearance grey white Standard atomic weight 85. ...


In 1985 at the University of Rochester's Laboratory for Laser Energetics a breakthrough in creating ultrashort-pulse, very high-intensity (terawatts) laser pulses became available using a technique called chirped pulse amplification, or CPA, discovered by Gérard Mourou. These high intensity pulses can produce filament propagation in the atmosphere.
The University of Rochester (UR) is a private, coeducational and nonsectarian research university located in Rochester, New York. ... The Laboratory for Laser Energetics (LLE) is a scientific research facility which is part of the University of Rochesters south campus, located in Rochester, New York. ... This page lists examples of the power in watts produced by various different sources of energy. ... Chirped pulse amplification (CPA) or optical parametric chirped pulse amplification, is a technique for amplifying an ultrashort laser pulse up to the petawatt level with the laser pulse being stretched out temporally and spectrally prior to amplification. ... Gérard Mourou is a pioneer in the field of electrical engineering and lasers. ... In nonlinear optics, filament propagation is propagation of a beam of light through a medium without diffraction. ...


Types and operating principles

For a more complete list of laser types see this list of laser types.
Spectral output of several types of lasers.
Spectral output of several types of lasers.

An immense slab of continuous melt processed neodymium doped laser glass for use on the National Ignition Facility. ... Image File history File links Laser_spectral_lines. ... Image File history File links Laser_spectral_lines. ...

Gas lasers

Gas lasers using many gases have been built and used for many purposes. The gas laser is a kind of laser in which some sort of gas (such as helium or neon) is discharged to produce the laser light. ... For other uses, see Gas (disambiguation). ...


The helium-neon laser (HeNe) emits at a variety of wavelengths and units operating at 633 nm are very common in education because of its low cost. A helium-neon laser, usually called a HeNe laser, is a type of small gas laser. ...


Carbon dioxide lasers can emit hundreds of kilowatts[14] at 9.6 µm and 10.6 µm, and are often used in industry for cutting and welding. The efficiency of a CO2 laser is over 10%. A test target is vaporized and bursts into flame upon irradiation by a high power continuous wave carbon dioxide laser emitting tens of kilowatts of infrared light. ... A micrometre (American spelling: micrometer, symbol µm) is an SI unit of length. ...


Argon-ion lasers emit light in the range 351-528.7 nm. Depending on the optics and the laser tube a different number of lines is usable but the most commonly used lines are 458 nm, 488 nm and 514.5 nm. From left to right: 1 mW Uniphase HeNe on alignment-rig, 2 Watt Lexel 88 Argon Ion laser, and power-supply. ...


A nitrogen transverse electrical discharge in gas at atmospheric pressure (TEA) laser is an inexpensive gas laser producing UV Light at 337.1 nm.[15] // Overview A TEA Laser is one of the most easily (at least compared with other models) and inexpensive way to generate laser light. ...


Metal ion lasers are gas lasers that generate deep ultraviolet wavelengths. Helium-silver (HeAg) 224 nm and neon-copper (NeCu) 248 nm are two examples. These lasers have particularly narrow oscillation linewidths of less than 3 GHz (0.5 picometers),[16] making them candidates for use in fluorescence suppressed Raman spectroscopy. Ultraviolet (UV) radiation is electromagnetic radiation of a wavelength shorter than that of the visible region, but longer than that of soft X-rays. ... General Name, symbol, number helium, He, 2 Chemical series noble gases Group, period, block 18, 1, s Appearance colorless Standard atomic weight 4. ... This article is about the chemical element. ... For other uses, see Neon (disambiguation). ... For other uses, see Copper (disambiguation). ... The Q factor or quality factor is a measure of the quality of a resonant system. ... A gigahertz is a billion hertz or a thousand megahertz, a measure of frequency. ... ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ... This article or section does not cite any references or sources. ...


Chemical lasers

Chemical lasers are powered by a chemical reaction, and can achieve high powers in continuous operation. For example, in the Hydrogen fluoride laser (2700-2900 nm) and the Deuterium fluoride laser (3800 nm) the reaction is the combination of hydrogen or deuterium gas with combustion products of ethylene in nitrogen trifluoride. They were invented by George C. Pimentel. A chemical laser is a laser that obtains its energy from a chemical reaction. ... Hydrogen fluoride laser is an infrared chemical laser. ... Hydrogen fluoride laser is an infrared chemical laser. ... Ethylene (or IUPAC name ethene) is the chemical compound with the formula C2H4. ... Nitrogen trifluoride, NF3, is a colorless, toxic, nonflammable, corrosive gas shipped in cylinders at high pressure. ... George C. Pimentel (1922–1989) was the inventor of the chemical laser. ...


Excimer lasers

Excimer lasers are powered by a chemical reaction involving an excited dimer, or excimer, which is a short-lived dimeric or heterodimeric molecule formed from two species (atoms), at least one of which is in an excited electronic state. They typically produce ultraviolet light, and are used in semiconductor photolithography and in LASIK eye surgery. Commonly used excimer molecules include F2 (fluorine, emitting at 157 nm), and noble gas compounds (ArF [193 nm], KrCl [222 nm], KrF [248 nm], XeCl [308 nm], and XeF [351 nm]).[17] An excimer laser is a form of ultraviolet chemical laser which is commonly used in eye surgery and semiconductor manufacturing. ... An excimer[1] (originally short for excited dimer) is a short-lived dimeric or heterodimeric molecule formed from two species, at least one of which is in an electronic excited state. ... After absorbing energy, an electron may jump from the ground state to a higher energy excited state. ... For other uses, see Ultraviolet (disambiguation). ... Photolithography is a process used in semiconductor device fabrication to transfer a pattern from a photomask (also called reticle) to the surface of a substrate. ... LASIK is the acronym for Laser-Assisted in Situ Keratomileusis, a type of refractive laser eye surgery performed by ophthalmologists for correcting myopia, hyperopia, and astigmatism. ... Distinguished from fluorene and fluorone. ...


Solid-state lasers

A 50 W FASOR, based on a Nd:YAG laser, used at the Starfire Optical Range
A 50 W FASOR, based on a Nd:YAG laser, used at the Starfire Optical Range

Solid state laser materials are commonly made by doping a crystalline solid host with ions that provide the required energy states. For example, the first working laser was a ruby laser, made from ruby (chromium-doped corundum). Formally, the class of solid-state lasers includes also fiber laser, as the active medium (fiber) is in the solid state. Practically, in the scientific literature, solid-state laser usually means a laser with bulk active medium; while wave-guide lasers are caller fiber lasers. Image File history File linksMetadata Download high resolution version (2000x3008, 4406 KB) Original caption: Though the caption states that this is a sodium laser, this is actually misleading as the lasing medium in the Starfire Optical Range LIDAR laser seen here is really a dye laser which is tuned to... Image File history File linksMetadata Download high resolution version (2000x3008, 4406 KB) Original caption: Though the caption states that this is a sodium laser, this is actually misleading as the lasing medium in the Starfire Optical Range LIDAR laser seen here is really a dye laser which is tuned to... A 50W FASOR used at the Starfire Optical Range In physics, a FASOR is an acronym for Frequency Addition Source of Optical Radiation. ... The Starfire Optical Range, as viewed from a helicopter. ... A solid-state laser is a laser that uses a gain medium that is a solid, rather than a liquid such as dye lasers or a gas such as gas lasers. ... Diagram of the first ruby laser. ... This article is about the mineral. ... REDIRECT [[ Insert text]]EWWWWWWWWWWWWW YO General Name, symbol, number chromium, Cr, 24 Chemical series transition metals Group, period, block 6, 4, d Appearance silvery metallic Standard atomic weight 51. ... Corundum (from Tamil kurundam) is a crystalline form of aluminium oxide and one of the rock-forming minerals. ... A fiber laser or fibre laser is a laser in which the active gain medium is an optical fiber doped with rare-earth elements such as erbium or ytterbium. ... A solid-state laser is a laser that uses a gain medium that is a solid, rather than a liquid such as dye lasers or a gas such as gas lasers. ... A fiber laser or fibre laser is a laser in which the active gain medium is an optical fiber doped with rare-earth elements such as erbium or ytterbium. ...


Neodymium is a common dopant in various solid state laser crystals, including yttrium orthovanadate (Nd:YVO4), yttrium lithium fluoride (Nd:YLF) and yttrium aluminium garnet (Nd:YAG). All these lasers can produce high powers in the infrared spectrum at 1064 nm. They are used for cutting, welding and marking of metals and other materials, and also in spectroscopy and for pumping dye lasers. These lasers are also commonly frequency doubled, tripled or quadrupled to produce 532 nm (green, visible), 355 nm (UV) and 266 nm (UV) light when those wavelengths are needed. General Name, Symbol, Number neodymium, Nd, 60 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white, yellowish tinge Standard atomic weight 144. ... Yttrium orthovanadate (YVO4) is a transparent crystal. ... Neodymium-doped yttrium orthovanadate (Nd:YVO4) is a crystalline material formed by adding neodymium ions to yttrium orthovanadate. ... Yttrium lithium fluoride (LiYF4, sometimes abbreviated YLF) is a birefringent crystal, typically doped with neodymium and used as a gain medium in solid-state lasers. ... Yttrium aluminium garnet (YAG, Y3Al5O12) is a synthetic crystalline material of the garnet group, used as the active laser medium in various solid-state lasers. ... Acronym for Neodymium-doped Yttrium Aluminum Garnet, a compound that is used as the lasing medium for certain solid-state lasers. ... For other uses, see Infrared (disambiguation). ... Animation of the dispersion of light as it travels through a triangular prism. ... Close-up of a table-top dye laser based on Rhodamine 6G, emitting at 580 nm (yellow-orange). ... Nonlinear optics is the branch of optics that describes the behaviour of light in nonlinear media, that is, media in which the polarization P responds nonlinearly to the electric field E of the light. ... Nonlinear optics is the branch of optics that describes the behaviour of light in nonlinear media, that is, media in which the polarization P responds nonlinearly to the electric field E of the light. ... Nonlinear optics is the branch of optics that describes the behaviour of light in nonlinear media, that is, media in which the polarization P responds nonlinearly to the electric field E of the light. ... For other uses, see Green (disambiguation). ... Note: Ultraviolet is also the name of a 1998 UK television miniseries about vampires. ... Note: Ultraviolet is also the name of a 1998 UK television miniseries about vampires. ...


Ytterbium, holmium, thulium, and erbium are other common dopants in solid state lasers. Ytterbium is used in crystals such as Yb:YAG, Yb:KGW, Yb:KYW, Yb:SYS, Yb:BOYS, Yb:CaF2, typically operating around 1020-1050 nm. They are potentially very efficient and high powered due to a small quantum defect. Extremely high powers in ultrashort pulses can be achieved with Yb:YAG. Holmium-doped YAG crystals emit at 2097 nm and form an efficient laser operating at infrared wavelengths strongly absorbed by water-bearing tissues. The Ho-YAG is usually operated in a pulsed mode, and passed through optical fiber surgical devices to resurface joints, remove rot from teeth, vaporize cancers, and pulverize kidney and gall stones. Yb redirects here; for the unit of information see Yottabit General Name, Symbol, Number ytterbium, Yb, 70 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Standard atomic weight 173. ... General Name, Symbol, Number holmium, Ho, 67 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Atomic mass 164. ... General Name, Symbol, Number thulium, Tm, 69 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery gray Atomic mass 168. ... General Name, Symbol, Number erbium, Er, 68 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Standard atomic weight 167. ... General Name, Symbol, Number holmium, Ho, 67 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Atomic mass 164. ... For other uses, see Infrared (disambiguation). ...


Titanium-doped sapphire (Ti:sapphire) produces a highly tunable infrared laser, commonly used for spectroscopy as well as the most common ultrashort pulse laser. General Name, symbol, number titanium, Ti, 22 Chemical series transition metals Group, period, block 4, 4, d Appearance silvery grey-white metallic Standard atomic weight 47. ... Part of a Ti:sapphire oscillator. ... Tunable lasers are used in DWDM-systems to allow wavelength (frequency) changes controlled by the operator. ... For other uses, see Infrared (disambiguation). ... Animation of the dispersion of light as it travels through a triangular prism. ... In optics, an ultrashort pulse of light is an electromagnetic pulse whose time duration is on the order of the femtosecond ( second). ...


Thermal limitations in solid-state lasers arise from unconverted pump power that manifests itself as heat and phonon energy. This heat, when coupled with a high thermo-optic coefficient (dn/dT) can give rise to thermal lensing as well as reduced quantum efficiency. These types of issues can be overcome by another novel diode-pumped solid state laser, the diode-pumped thin disk laser. The thermal limitations in this laser type are mitigated by utilizing a laser medium geometry in which the thickness is much smaller than the diameter of the pump beam. This allows for a more even thermal gradient in the material. Thin disk lasers have been shown to produce up to kilowatt levels of power.[18] Normal modes of vibration progression through a crystal. ... // An optically-pumped disk laser A disk laser is a type of solid-state laser characterized by a heat drain and laser output that are realized on opposite sides of a thin layer of active medium. ... // An optically-pumped disk laser A disk laser is a type of solid-state laser characterized by a heat drain and laser output that are realized on opposite sides of a thin layer of active medium. ...


Fiber-hosted lasers

Solid-state lasers where the light is guided due to the total internal reflection in an optical fiber are called fiber lasers. Guiding of light allows extremely long gain regions providing good cooling conditions; fibers have high surface area to volume ratio which allows efficient cooling. In addition, the fiber's waveguiding properties tend to reduce thermal distortion of the beam. Erbium and ytterbium ions are common active species in such lasers. Critical angle redirects here. ... Optical fibers An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length. ... A fiber laser or fibre laser is a laser in which the active gain medium is an optical fiber doped with rare-earth elements such as erbium or ytterbium. ... General Name, Symbol, Number erbium, Er, 68 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Standard atomic weight 167. ... Yb redirects here; for the unit of information see Yottabit General Name, Symbol, Number ytterbium, Yb, 70 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Standard atomic weight 173. ...


Quite often, the fiber laser is designed as a double-clad fiber. This type of fiber consists of a fiber core, an inner cladding and an outer cladding. The index of the three concentric layers is chosen so that the fiber core acts as a single-mode fiber for the laser emission while the outer cladding acts as a highly multimode core for the pump laser. This lets the pump propagate a large amount of power into and through the active inner core region, while still having a high numerical aperture (NA) to have easy launching conditions. In fiber optics, a double-clad fiber (or doubly clad fiber) is an optical fiber that has a relatively small-diameter core and two layers of large-diameter cladding. ...


Pump light can be used more efficiently by creating a fiber disk laser, or a stack of such lasers.


Fiber lasers have a fundamental limit in that the intensity of the light in the fiber cannot be so high that optical nonlinearities induced by the local electric field strength can become dominant and prevent laser operation and/or lead to the material destruction of the fiber. This effect is called photodarkening. In bulk laser materials, the cooling is not so efficient, and it is difficult to separate the effects of photodarkening from the thermal effects, but the experiments in fibers show that the photodarkening can be attributed to the formation of long-living color centers.[citation needed] The colour centre is a region in the human brain responsible for processing colour. ...


Photonic crystal lasers

Photonic crystal lasers are lasers based on nano-structures that provide the mode confinement and the density of optical states (DOS) structure required for the feedback to take place[clarify]. They are typical micron-sized and tunable on the bands of the photonic crystals. [2][clarify] Density of states (DOS) is a property in statistical and condensed matter physics that quantifies how closely packed energy levels are in some physical system. ...


Semiconductor lasers

Commercial laser diodes emit at wavelengths from 375 nm to 1800 nm, and wavelengths of over 3 µm have been demonstrated. Low power laser diodes are used in laser printers and CD/DVD players. More powerful laser diodes are frequently used to optically pump other lasers with high efficiency. The highest power industrial laser diodes, with power up to 10 kW (70dBm), are used in industry for cutting and welding. External-cavity semiconductor lasers have a semiconductor active medium in a larger cavity. These devices can generate high power outputs with good beam quality, wavelength-tunable narrow-linewidth radiation, or ultrashort laser pulses. A packaged laser diode with penny for scale. ... 1993 Apple LaserWriter Pro 630 laser printer A laser printer is a common type of computer printer that rapidly produces high quality text and graphics on plain paper. ... Laser pumping is the act of energy transfer from an external source into the laser gain medium. ... The Q factor or quality factor is a measure of the quality of a resonant system. ...

A small laser diode, most likely from a CD player or a DVD player.
A small laser diode, most likely from a CD player or a DVD player.

Vertical cavity surface-emitting lasers (VCSELs) are semiconductor lasers whose emission direction is perpendicular to the surface of the wafer. VCSEL devices typically have a more circular output beam than conventional laser diodes, and potentially could be much cheaper to manufacture. As of 2005, only 850 nm VCSELs are widely available, with 1300 nm VCSELs beginning to be commercialized,[19] and 1550 nm devices an area of research. VECSELs are external-cavity VCSELs. Quantum cascade lasers are semiconductor lasers that have an active transition between energy sub-bands of an electron in a structure containing several quantum wells. Image File history File links Download high resolution version (3060x2036, 1070 KB)original caption: This technology is known as a Tunable Diode Laser (TDL) gas sensor. ... Image File history File links Download high resolution version (3060x2036, 1070 KB)original caption: This technology is known as a Tunable Diode Laser (TDL) gas sensor. ... CD may stand for: Compact Disc Canadian Forces Decoration Cash Dispenser (at least used in Japan) CD LPMud Driver Centrum-Demokraterne (Centre Democrats of Denmark) Certificate of Deposit České Dráhy (Czech Railways) Chad (NATO country code) Chalmers Datorförening (computer club of the Chalmers University of Technology) a 1960s... DVD (also known as Digital Versatile Disc or Digital Video Disc - see Etymology) is a popular optical disc storage media format. ... Diagram of a simple VCSEL structure. ... A Vertical-External-Cavity Surface-Emitting-Laser (VECSEL) is a small, tunable semiconductor laser similar to a VCSEL. VECSELs are used primarily as near infrared devices in laser cooling and spectroscopy. ... The quantum cascade laser or QC laser is a unipolar laser which uses electrons as its only charge carrier. ... A quantum well is a potential well that confines particles in one dimension, forcing them to occupy a planar region. ...


The development of a silicon laser is important in the field of optical computing, since it means that if silicon, the chief ingredient of computer chips, were able to produce lasers, it would allow the light to be manipulated like electrons are in normal integrated circuits. Thus, photons would replace electrons in the circuits, which dramatically increases the speed of the computer. Unfortunately, silicon is a difficult lasing material to deal with, since it has certain properties which block lasing. However, recently teams have produced silicon lasers through methods such as fabricating the lasing material from silicon and other semiconductor materials, such as indium(III) phosphide or gallium(III) arsenide, materials which allow coherent light to be produced from silicon. These are called hybrid silicon laser. Another type is a Raman laser, which takes advantage of Raman scattering to produce a laser from materials such as silicon. Not to be confused with Silicone. ... An Optical Computer is a computer that performs its computation with photons as opposed to the more traditional electron-based computation. ... A microchip is, properly, an integrated circuit (IC). ... Flash point Non-flmmable. ... This article is about the chemical compound. ... A hybrid silicon laser is a semiconductor laser fabricated from both silicon and group III-V semiconductor materials. ... The Raman laser is a byproduct of the Raman Effect, discovered in 1928 by Nobel laureate Chandrasekhara Venkata Raman. ... Raman scattering or the Raman effect is the inelastic scattering of a photon. ...


Dye lasers

Dye lasers use an organic dye as the gain medium. The wide gain spectrum of available dyes allows these lasers to be highly tunable, or to produce very short-duration pulses (on the order of a few femtoseconds) Close-up of a table-top dye laser based on Rhodamine 6G, emitting at 580 nm (yellow-orange). ... A femtosecond is the SI unit of time equal to 10-15 of a second. ...


Free electron lasers

Free electron lasers, or FELs, generate coherent, high power radiation, that is widely tunable, currently ranging in wavelength from microwaves, through terahertz radiation and infrared, to the visible spectrum, to soft X-rays. They have the widest frequency range of any laser type. While FEL beams share the same optical traits as other lasers, such as coherent radiation, FEL operation is quite different. Unlike gas, liquid, or solid-state lasers, which rely on bound atomic or molecular states, FELs use a relativistic electron beam as the lasing medium, hence the term free electron. X-ray free electronic laser schema of operation A free electron laser, or FEL, is a laser that shares the same optical properties as conventional lasers such as emitting a beam consisting of coherent electromagnetic radiation which can reach high power, but which uses some very different operating principles to... Electromagnetic waves sent at terahertz frequencies, known as terahertz radiation, terahertz waves, terahertz light, T-rays, T-light, T-lux and THz, are in the region of the electromagnetic spectrum between 300 gigahertz (3x1011 Hz) and 3 terahertz (3x1012 Hz), corresponding to the wavelength range starting at submillimeter (<1 millimeter...


Exotic laser media

In September 2007, the BBC News reported that there was speculation about the possibility of using positronium annihilation to drive a very powerful gamma ray laser.[20] Dr. David Cassidy of the University of California, Riverside proposed that a single such laser could be used to ignite a nuclear fusion reaction, replacing the hundreds of lasers used in typical inertial confinement fusion experiments.[20] This article refers to the news department of the British Broadcasting Corporation, for the BBC News Channel see BBC News (TV channel). ... Positronium (Ps) is a system consisting of an electron and its anti-particle, a positron, bound together into an exotic atom. The orbit of the two particles and the set of energy levels is similar to that of the hydrogen atom (electron and proton). ... For other uses, see Annihilation (disambiguation). ... This article is about electromagnetic radiation. ... The University of California, Riverside, commonly known as UCR or UC Riverside, is a public research university and one of 10 campuses of the University of California system. ... The deuterium-tritium (D-T) fusion reaction is considered the most promising for producing sustainable fusion power. ... Inertial confinement fusion using lasers rapidly progressed in the late 1970s and early 1980s from being able to deliver only a few joules of laser energy (per pulse) to a fusion target to being able to deliver tens of kilojoules to a target. ...


Space-based X-ray lasers pumped by a nuclear explosion have also been proposed as antimissile weapons.[citation needed] Such devices would be one-shot weapons.


Uses

Lasers range in size from microscopic diode lasers (top) with numerous applications, to football field sized neodymium glass lasers (bottom) used for inertial confinement fusion, nuclear weapons research and other high energy density physics experiments
Lasers range in size from microscopic diode lasers (top) with numerous applications, to football field sized neodymium glass lasers (bottom) used for inertial confinement fusion, nuclear weapons research and other high energy density physics experiments
Main article: Laser applications

When lasers were invented in 1960, they were called "a solution looking for a problem".[21] Since then, they have become ubiquitous, finding utility in thousands of highly varied applications in every section of modern society, including consumer electronics, information technology, science, medicine, industry, law enforcement, entertainment, and the military. Image File history File links Download high resolution version (2720x3500, 2538 KB)Composite image formed from [1] and [2] showing huge range of sizes of different lasers. ... Image File history File links Download high resolution version (2720x3500, 2538 KB)Composite image formed from [1] and [2] showing huge range of sizes of different lasers. ... A laser diode is a laser where the active medium is a semiconductor p-n junction similar to that found in a light-emitting diode. ... General Name, Symbol, Number neodymium, Nd, 60 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white, yellowish tinge Standard atomic weight 144. ... This article is about the material. ... Inertial confinement fusion using lasers rapidly progressed in the late 1970s and early 1980s from being able to deliver only a few joules of laser energy (per pulse) to a fusion target to being able to deliver tens of kilojoules to a target. ... The mushroom cloud of the atomic bombing of Nagasaki, Japan, 1945, rose some 18 kilometers (11 mi) above the hypocenter A nuclear weapon derives its destructive force from nuclear reactions of fusion or fission. ... There are many scientific, military, medical and commercial laser applications which have been developed since the invention of the laser in the 1958. ... Consumer electronics is a term used to describe the category of electronic equipment intended for everyday use by people, the consumers. ... Information and communication technology spending in 2005 Information Technology (IT), as defined by the Information Technology Association of America (ITAA), is the study, design, development, implementation, support or management of computer-based information systems, particularly software applications and computer hardware. ... A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... For the chemical substances known as medicines, see medication. ... For the band, see The Police. ... A stilt-walker entertaining shoppers at a shopping centre in Swindon, England Entertainment is an activity designed to give pleasure or relaxation to an audience (although in the case of a computer game the audience may be only one person). ...


The first application of lasers visible in the daily lives of the general population was the supermarket barcode scanner, introduced in 1974. The laserdisc player, introduced in 1978, was the first successful consumer product to include a laser, but the compact disc player was the first laser-equipped device to become truly common in consumers' homes, beginning in 1982, followed shortly by laser printers. For the taxonomic method, see DNA barcoding. ... Not to be confused with disk laser, a type of solid-state laser in a flat configuration. ... CD redirects here. ... 1993 Apple LaserWriter Pro 630 laser printer A laser printer is a common type of computer printer that rapidly produces high quality text and graphics on plain paper. ...


Some of the other applications include:

In 2004, excluding diode lasers, approximately 131,000 lasers were sold world-wide, with a value of US$2.19 billion.[22] In the same year, approximately 733 million diode lasers, valued at $3.20 billion, were sold.[23] For the chemical substances known as medicines, see medication. ... The last twenty years have witnessed a surge of interest in bloodless surgery, for a variety of reasons. ... “Surgeon” redirects here. ... “Bladder stone” redirects here. ... Laser and non-laser surgery While the terms laser eye surgery and refractive surgery are commonly used as if they were interchangeable, this is not the case. ... This article is about the dental profession. ... Welding is a fabrication process that joins materials, usually metals or thermoplastics, by causing coalescence. ... In military science, defense (or defence) is the art of preventing an enemy from conquering territory. ... Munition is often defined as a synonyn for ammunition. ... The Airborne Laser (ABL) weapons system is designed to shoot down ballistic missiles in their boost stage. ... The Directional Infrared Counter Measures (DIRCM) is a system produced by Northrop Grumman to protect aircraft from shoulder-fired infrared (heat seeking) missiles. ... For other uses, see Radar (disambiguation). ... This article is about the concept. ... Animation of the dispersion of light as it travels through a triangular prism. ... Guo et al. ... Anneal may refer to: Annealing (metallurgy), a heat treatment wherein the microstructure of a material is altered, causing changes in its properties such as strength and hardness. ... Scattering is a general physical process whereby some forms of radiation, such as light, sound or moving particles, for example, are forced to deviate from a straight trajectory by one or more localized non-uniformities in the medium through which it passes. ... It has been suggested that Optical interferometry be merged into this article or section. ... A FASOR used at the Starfire Optical Range for LIDAR and laser guide star experiments is tuned to the sodium D2a line and used to excite sodium atoms in the upper atmosphere. ... 1993 Apple LaserWriter Pro 630 laser printer A laser printer is a common type of computer printer that rapidly produces high quality text and graphics on plain paper. ... CD redirects here. ... For the taxonomic method, see DNA barcoding. ... A clinical mercury thermometer A thermometer is a device that measures temperature or temperature gradient, using a variety of different principles. ... A keychain laser pointer. ... Holography (from the Greek, Όλος-holos whole + γραφή-graphe writing) is the science of producing holograms, an advanced form of photography that allows an image to be recorded in three dimensions. ...


Examples by power

Different uses need lasers with different output powers. Lasers that produce a continuous beam or a series of short pulses can be compared on the basis of their average power. Lasers that produce pulses can also be characterized based on the peak power of each pulse. The peak power of a pulsed laser is many orders of magnitude greater than its average power. The average output power is always less than the power consumed. An order of magnitude is the class of scale or magnitude of any amount, where each class contains values of a fixed ratio to the class preceding it. ...


The continuous or average power required for some uses:

  • 5 mW – CD-ROM drive
  • 5–10 mW – DVD player or DVD-ROM drive
  • 100 mW – CD-RW drive
  • 250 mW – High-speed CD-R burner[24]
  • 500 mW – Consumer DVD-R burner[25]
  • 1 W – green laser in current Holographic Versatile Disc prototype development
  • 1–20 W – output of the majority of commercially available solid-state lasers used for micro machining
  • 30–100 W – typical sealed CO2 surgical lasers[26]
  • 100–3000 W (peak output 1.5 kW) – typical sealed CO2 lasers used in industrial laser cutting
  • 1 kW – Output power expected to be achieved by a prototype 1 cm diode laser bar[27]

Examples of pulsed systems with high peak power: The CD-ROM (an abbreviation for Compact Disc Read-Only Memory (ROM)) is a non-volatile optical data storage medium using the same physical format as audio compact discs, readable by a computer with a CD-ROM drive. ... The inside of a DVD player A DVD player is a device not only playing discs produced under the DVD Video standard but also playing discs under the standard of DVD Audio. ... Compact Disc ReWritable (CD-RW) is a rewritable optical disc format. ... This article does not cite any references or sources. ... A DVD+R disc The title given to this article is incorrect due to technical limitations. ... Picture of an HVD by Optware. ... Laser cutting is a technology which uses a laser to cut materials, and is usually used in industrial manufacturing. ...

This page lists examples of the power in watts produced by various different sources of energy. ... A construction worker inside NIFs 10 meter target chamber. ... This page lists examples of the power in watts produced by various different sources of energy. ... 1998 is a common year starting on Thursday of the Gregorian calendar, and was designated the International Year of the Ocean. ... Aerial view of the lab and surrounding area. ...

Hobby uses

In recent years, some hobbyists have taken interests in lasers. Lasers used by hobbyists are generally of class IIIa or IIIb, although some have made their own class IV types.[30] However, compared to other hobbyists, laser hobbyists are far less common, due to the cost and potential dangers involved. Due to the cost of lasers, some hobbyists use inexpensive means to obtain lasers, such as extracting diodes from DVD burners.[31] An Apple DVD-R Disc A spindle with 50 Verbatim DVD-R discs A single DVD-R Disc A DVD-Recordable or DVD-R (pronounced DVD Are or DVD Dash Are) is an optical disc with a larger storage capacity than a CD-R, typically 4. ...


Hobbyists also have been taking surplus pulsed lasers from retired military applications and modifying them for pulsed holography. Pulsed Ruby and Pulsed YAG lasers have been used.


Laser safety

Warning symbol for lasers
Warning symbol for lasers

Even the first laser was recognized as being potentially dangerous. Theodore Maiman characterized the first laser as having a power of one "Gillette"; as it could burn through one Gillette razor blade. Today, it is accepted that even low-power lasers with only a few milliwatts of output power can be hazardous to human eyesight. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... A typical laser warning symbol. ... Under certain conditions, laser light or other bright lights (spotlights, searchlights) directed at aircraft can be a hazard. ... Theodore Maiman. ... Unusual units of measurement are sometimes used by scientists, especially physicists and mathematicians, and other technically-minded people such as engineers and programmers, as bits of dry humor combined with putative practical convenience. ... Global Gillette is a business unit of Procter & Gamble. ... Occams Razor or Hanlons razor A razor is a an edge tool (primarily, used in shaving). ...


At wavelengths which the cornea and the lens can focus well, the coherence and low divergence of laser light means that it can be focused by the eye into an extremely small spot on the retina, resulting in localized burning and permanent damage in seconds or even less time. Lasers are classified into safety classes numbered I (inherently safe) to IV (even scattered light can cause eye and/or skin damage). Laser products available for consumers, such as CD players and laser pointers are usually in class I, II, or III. Certain infrared lasers with wavelengths beyond about 1.4 micrometres are often referred to as being "eye-safe". This is because the intrinsic molecular vibrations of water molecules very strongly absorb light in this part of the spectrum, and thus a laser beam at these wavelengths is attenuated so completely as it passes through the eye's cornea that no light remains to be focused by the lens onto the retina. The label "eye-safe" can be misleading, however, as it only applies to relatively low power continuous wave beams and any high power or q-switched laser at these wavelengths can burn the cornea, causing severe eye damage. The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber, providing most of an eyes optical power [1]. Together with the lens, the cornea refracts light and, as a result, helps the eye to focus. ... For other uses, see Eye (disambiguation). ... Human eye cross-sectional view. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber, providing most of an eyes optical power [1]. Together with the lens, the cornea refracts light and, as a result, helps the eye to focus. ... Human eye cross-sectional view. ... Q-switching, sometimes known as giant pulse formation, is a technique discovered circa 1962 by R.W. Hellwarth and F.J. McClung using electrically switched Kerr cell shutters and is a technique by which a laser can be made to produce a pulsed output beam. ...


'High Powered' green handheld 125milliwatt lasers (considered 'High Power' compared to a normal laser pointer) have recently been used in attacks on aircraft pilots landing at Australian airports. The risk is that if the laser hit the pilots eyes it could cause temporary blindness at a critical point in the flight. In 2007 penalties under the Australian Civil Aviation Act for shining laser beams at aircraft were increased to two years' jail and fines of up to $30,000.[citation needed]


Fictional predictions

For lasers in fiction, see also the raygun.

Before stimulated emission was discovered, novelists used to describe machines that we can identify as "lasers". // Rayguns are a type of directed-energy weapon. ... In optics, stimulated emission is the process by which, when perturbed by a photon, matter may lose energy resulting in the creation of another photon. ... A novel is an extended work of written, narrative, prose fiction, usually in story form; the writer of a novel is a novelist. ...

  • The first fictional device similar to a military CO2 laser (see Heat-Ray) appears in the sci-fi novel The War of the Worlds by H. G. Wells in 1898.
  • A laser-like device was described in Alexey Tolstoy's sci-fi novel The Hyperboloid of Engineer Garin in 1927.
  • Mikhail Bulgakov exaggerated the biological effect (laser biostimulation) of intensive red light in his sci-fi novel Fatal Eggs (1925), without any reasonable description of the source of this red light. (In that novel, the red light first appears occasionally from the illuminating system of an advanced microscope; then the protagonist Prof. Persikov arranges the special set-up for generation of the red light.)

The Heat-Ray is the primary offensive weapon used by the Martians in the H. G. Wellss classic science fiction novel The War of the Worlds. ... The War of the Worlds (1898), by H. G. Wells, is an early science fiction novel (or novella) which describes an invasion of England by aliens from Mars. ... Herbert George Wells (September 21, 1866 – August 13, 1946), better known as H. G. Wells, was an English writer best known for such science fiction novels as The Time Machine, The War of the Worlds, The Invisible Man, The First Men in the Moon and The Island of Doctor Moreau. ... Aleksei Nikolaevich Tolstoi. ... Book cover (Russian edition). ... Mikhail Afanasievich Bulgakov (Russian: Михаил Афанасьевич Булгаков; May 15 [O.S. May 3] 1891, Kiev – March 10, 1940, Moscow) was a Russian novelist and playwright of the first half of the 20th century. ... The Fatal Eggs (Russian: Роковые яйца, IPA: ) is a novella by Mikhail Bulgakov, a Soviet novelist and playwright whose most famous work is Master and Margarita. ...

See also

Here, we list the acronyms of laser physics, applications and technology. ... There are many scientific, military, medical and commercial laser applications which have been developed since the invention of the laser in the 1958. ... A laser system generally consists of three important parts: An energy source (usually referred to as the pump or pump source); A gain medium or laser medium; A mirror, or system of mirrors, forming an optical resonator. ... Laser converting is a production technology that enables device manufacturers to produce features that otherwise would be problematic or even impossible to die-cut—without the need for tooling. ... Laser cutting is a technology which uses a laser to cut materials, and is usually used in industrial manufacturing. ... Laser engraving is the practice of using lasers to engrave or mark an object (it is also sometimes incorrectly described as etching, which involves the use of acid or a similar chemical). ... Guo et al. ... A laser scalpel is a scalpel for surgery, cutting tissue by the energy of laser light. ... A 3D scanner is a device that analyzes a real-world object or environment to collect data on its shape and possibly color. ... A laser accelerometer comprises a frame having three orthogonal input axes and multiple proof masses, each proof mass having a predetermined blanking surface. ... Laser science is a branch of optics that describes the theory and practice of lasers. ... Laser beam welding is a technique in manufacturing whereby two or more pieces of material (usually metal) are joined by together through use of a laser beam. ... A Bessel beam is a beam of electromagnetic radiation whose intensity is described by a Bessel function. ... Copper Bromide laser in operation. ... A keychain laser pointer. ... A laser turntable is a phonograph that plays gramophone records using a laser beam as the pickup, rather than a conventional stylus. ... This article is about the photographic technique. ... In physics, induced gamma emission (IGE) refers to the process of fluorescent emission of gamma rays from excited nuclei, or from nuclear isomers. ... The International Laser Display Association (ILDA) is the world organization dedicated to advancing the use of laser displays in art, entertainment and education. ... A Common Household Light bulb This is a list of sources of light, including both natural and artificial sources, and both processes and devices. ... A hydrogen radio frequency discharge, the first element inside a hydrogen maser (see description below) A maser is a device that produces coherent electromagnetic waves through amplification due to stimulated emission. ... An optical amplifier is a device that amplifies an optical signal directly, without the need to first convert it to an electrical signal. ... // Rayguns are a type of directed-energy weapon. ... Selective Laser Sintering (SLS®, a registered trademark of 3D Systems, Inc. ... In optical systems, a speckle pattern is a field-intensity pattern produced by the mutual interference of partially coherent beams that are subject to minute temporal and spatial fluctuations. ... In optics, a Tophat beam is a Laser beam with a near-uniform fluence (energy density) within a circular disk. ... If an optical emitter (e. ... The Airborne Laser (ABL) weapons system is designed to shoot down ballistic missiles in their boost stage. ...

Notes and references

  1. ^ a b Gould, R. Gordon (June 1959). "The LASER, Light Amplification by Stimulated Emission of Radiation". The Ann Arbor Conference on Optical Pumping. 
  2. ^ laser. Reference.com. Retrieved on 2008-05-15.
  3. ^ Townes, Charles Hard. The first laser. University of Chicago. Retrieved on 2008-05-15.
  4. ^ Schawlow and Townes invent the laser. Lucent Technologies (1998). Retrieved on 2006-10-24.
  5. ^ Dictionary.com - "lase"
  6. ^ G.P. Karman, G.S. McDonald, G.H.C. New, J.P. Woerdman, "Laser Optics: Fractal modes in unstable resonators", Nature, Vol. 402, 138, 11 November 1999.
  7. ^ Steen, W. M. "Laser Materials Processing", 2nd Ed. 1998.
  8. ^ (Italian) Il rischio da laser: cosa è e come affrontarlo; analisi di un problema non così lontano da noi ("The risk from laser: what it is and what it is like facing it; analysis of a problem which is thus mot far away from us."), PROGRAMMA CORSO DI FORMAZIONE OBBLIGATORIO ANNO 2004, Dimitri Batani (Powerpoint presentation >7Mb). Retrieved 1 January 2007.
  9. ^ Steen, W. M. "Laser Materials Processing", 2nd Ed. 1998.
  10. ^ The Nobel Prize in Physics 1966 Presentation Speech by Professor Ivar Waller. Retrieved 1 January 2007.
  11. ^ Chu, Steven; Townes, Charles (2003). "Arthur Schawlow", in ed. Edward P. Lazear,: Biographical Memoirs, vol. 83, National Academy of Sciences, p. 202. ISBN 0-309-08699-X. 
  12. ^ Maiman, T.H. (1960). "Stimulated optical radiation in ruby". Nature 187 (4736): 493–494. 
  13. ^ Hecht, Jeff (2005). Beam: The Race to Make the Laser. Oxford University Press. ISBN 0-19-514210-1. 
  14. ^ Air Force Research Lab's high power CO2 laser. Defense Tech Briefs.
  15. ^ Csele, Mark (2004). The TEA Nitrogen Gas Laser. Homebuilt Lasers Page. Retrieved on 2007-09-15.
  16. ^ Deep UV Lasers. Photon Systems, Covina, Calif. Retrieved on 2007-05-27.
  17. ^ Schuocker, D. (1998). Handbook of the Eurolaser Academy. Springer. ISBN 0412819104. 
  18. ^ C. Stewen, M. Larionov, and A. Giesen, “Yb:YAG thin disk laser with 1 kW output power,” in OSA Trends in Optics and Photonics, Advanced Solid State Lasers, H. Injeyan, U. Keller, and C. Marshall, ed. (Optical Society of America, Washington, DC., 2000) pp. 35-41.
  19. ^ "Picolight ships first 4-Gbit/s 1310-nm VCSEL transceivers", Laser Focus World, Dec. 9, 2005, accessed May 27, 2006
  20. ^ a b Fildes, Jonathan (2007-09-12). Mirror particles form new matter. BBC News. Retrieved on 2008-05-22.
  21. ^ Charles H. Townes (2003). "The first laser", in Laura Garwin and Tim Lincoln: A Century of Nature: Twenty-One Discoveries that Changed Science and the World. University of Chicago Press, 107-12. ISBN 0-226-28413-1. Retrieved on 2008-02-02. 
  22. ^ Kincade, Kathy and Stephen Anderson (2005) "Laser Marketplace 2005: Consumer applications boost laser sales 10%", Laser Focus World, vol. 41, no. 1. (online)
  23. ^ Steele, Robert V. (2005) "Diode-laser market grows at a slower rate", Laser Focus World, vol. 41, no. 2. (online)
  24. ^ Sony Corp. "250 mW semiconductor laser diodes that contribute to faster data write operations in CD-R/RW and 100 mW semiconductor laser diodes for DVD+R/RW and DVD-R/RW" Application note. URL accessed May 27, 2006.
  25. ^ Sony Corp. (pdf).
  26. ^ George M. Peavy, "How to select a surgical veterinary laser", veterinary-laser.com. URL accessed March 14, 2008.
  27. ^ Tyrell, James, "Diode lasers get fundamental push to higher power", Optics.org. URL accessed May 27, 2006.
  28. ^ Heller, Arnie, "Orchestrating the world's most powerful laser." Science and Technology Review. Lawrence Livermore National Laboratory, July/August 2005. URL accessed May 27, 2006.
  29. ^ Schewe, Phillip F.; Stein, Ben (November 9, 1998). Physics News Update 401. American Institute of Physics. Retrieved on 2008-03-15.
  30. ^ PowerLabs CO2 LASER! Sam Barros 21 June 2006. Retrieved 1 January 2007.
  31. ^ Howto: Make a DVD Burner into a High-Powered Laser

The first page of Gordon Goulds famous notebook, in which he coined the acronym LASER and described the essential elements for constructing one. ... Reference. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance with the Gregorian calendar. ... is the 135th day of the year (136th in leap years) in the Gregorian calendar. ... Charles Hard Townes (born July 28, 1915) is an American Nobel Prize-winning physicist and educator. ... For other uses, see University of Chicago (disambiguation). ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance with the Gregorian calendar. ... is the 135th day of the year (136th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 297th day of the year (298th in leap years) in the Gregorian calendar. ... is the 1st day of the year in the Gregorian calendar. ... is the 1st day of the year in the Gregorian calendar. ... Steven Chu (Chinese: ; pinyin: ), born 1948 in St. ... Charles Hard Townes (born July 28, 1915) is an American Nobel Prize-winning physicist and educator. ... Theodore Maiman. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 258th day of the year (259th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 147th day of the year (148th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 255th day of the year (256th in leap years) in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance with the Gregorian calendar. ... is the 142nd day of the year (143rd in leap years) in the Gregorian calendar. ... Charles Hard Townes (born July 28, 1915) is an American Nobel Prize-winning physicist and educator. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance with the Gregorian calendar. ... is the 33rd day of the year in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance with the Gregorian calendar. ... is the 74th day of the year (75th in leap years) in the Gregorian calendar. ... is the 172nd day of the year (173rd in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 1st day of the year in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ...

Further reading

Books
  • Bertolotti, Mario (1999, trans. 2004). The History of the Laser, Institute of Physics. ISBN 0-750-30911-3
  • Csele, Mark (2004). Fundamentals of Light Sources and Lasers, Wiley. ISBN 0-471-47660-9
  • Koechner, Walter (1992). Solid-State Laser Engineering, 3rd ed., Springer-Verlag. ISBN 0-387-53756-2
  • Siegman, Anthony E. (1986). Lasers, University Science Books. ISBN 0-935702-11-3
  • Silfvast, William T. (1996). Laser Fundamentals, Cambridge University Press. ISBN 0-521-55617-1
  • Svelto, Orazio (1998). Principles of Lasers, 4th ed. (trans. David Hanna), Springer. ISBN 0-306-45748-2
  • Taylor, Nick (2000). LASER: The inventor, the Nobel laureate, and the thirty-year patent war. New York: Simon & Schuster. ISBN 0-684-83515-0. 
  • Wilson, J. & Hawkes, J.F.B. (1987). Lasers: Principles and Applications, Prentice Hall International Series in Optoelectronics, Prentice Hall. ISBN 0-13-523697-5
  • Yariv, Amnon (1989). Quantum Electronics, 3rd ed., Wiley. ISBN 0-471-60997-8
Periodicals
  • Applied Physics B: Lasers and Optics (ISSN 0946-2171)
  • IEEE Journal of Lightwave Technology (ISSN 0733-8724)
  • IEEE Journal of Quantum Electronics (ISSN 0018-9197)
  • IEEE Journal of Selected Topics in Quantum Electronics (ISSN 1077-260X)
  • IEEE Photonics Technology Letters
  • Journal of the Optical Society of America B: Optical Physics (ISSN 0740-3224)
  • Laser Focus World (ISSN 0740-2511)
  • Optics Letters (ISSN 0146-9592)
  • Photonics Spectra (ISSN 0731-1230)

Pearson can mean Pearson PLC the media conglomerate. ... There are very few or no other articles that link to this one. ... Optics Letters is a peer reviewed rapid publication scientific journal published by the Optical Society of America. ...

External links

Wikimedia Commons has media related to:

HowStuffWorks is a website created by Marshall Brain but now owned by the Convex Group. ...


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