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Encyclopedia > Photonic crystal
The opal in this bracelet contains a natural periodic microstructure responsible for its iridescent color. It is essentially a natural photonic crystal, although it does not have a complete photonic band gap.
The opal in this bracelet contains a natural periodic microstructure responsible for its iridescent color. It is essentially a natural photonic crystal, although it does not have a complete photonic band gap.

Photonic crystals are periodic optical (nano)structures that are designed to affect the motion of photons in a similar way that periodicity of a semiconductor crystal affects the motion of electrons. Photonic crystals occur in nature and in various forms have been studied by science for the last 100 years. Image File history File links Opal_Armband_800pix. ... Image File history File links Opal_Armband_800pix. ... The iridescence of the Blue Morpho butterfly wings. ... See also list of optical topics. ... A nanostructure is an intermediate size between molecular and microscopic (micrometer-sized) structures. ... In physics, the photon (from Greek φως, phōs, meaning light) is the quantum of the electromagnetic field; for instance, light. ... A semiconductor is a solid whose electrical conductivity is in between that of a metal and that of an insulator, and can be controlled over a wide range, either permanently or dynamically. ... CRYSTAL is a quantum chemistry ab initio program, designed primarily for calculations on crystals (3 dimensions), slabs (2 dimensions) and polymers (1 dimension) using translational symmetry, but it can be used for single molecules. ... e- redirects here. ...

Contents

Introduction

Photonic crystals are composed of periodic dielectric or metallo-dielectric (nano)structures that affect the propagation of electromagnetic waves (EM) in the same way as the periodic potential in a semiconductor crystal affects the electron motion by defining allowed and forbidden electronic energy bands. Simply put, photonic crystals contain regularly repeating internal regions of high and low dielectric constant. Photons (manifesting in this case, their wave-like nature) propagate through this structure - or not - depending on their "wavelength". Wavelengths of light (stream of photons) that are allowed to travel are known as "modes". Disallowed bands of wavelengths are called photonic band gaps. This gives rise to distinct optical phenomena such as inhibition of spontaneous emission, high-reflecting omni-directional mirrors and low-loss-waveguiding amongst others. Since the basic physical phenomenon is based on diffraction, the periodicity of the photonic crystal structure has to be in the same length-scale as half the wavelength of the EM waves i.e. ~300 (blue) to 700 (red) nm for photonic crystals operating in the visible part of the spectrum - the repeating regions of high and low dielectric constants have to be of this order of dimension(!). This makes the fabrication of optical photonic cumbersome and complex. A dielectric, or electrical insulator, is a substance that is highly resistant to electric current. ... intermediate size between molecular and microscopic (micrometer-sized) structures ... Electromagnetic radiation or EM radiation is a combination (cross product) of oscillating electric and magnetic fields perpendicular to each other, moving through space as a wave, effectively transporting energy and momentum. ... In mathematics, a periodic function is a function that repeats its values, after adding some definite period to the variable. ... A semiconductor is a solid whose electrical conductivity is in between that of a metal and that of an insulator, and can be controlled over a wide range, either permanently or dynamically. ... e- redirects here. ... In solid state physics, the electronic band structure (or simply band structure) of a solid describes ranges of energy that an electron is forbidden or allowed to have. ... The wavelength is the distance between repeating units of a wave pattern. ... This article or section does not adequately cite its references or sources. ... Spontaneous emission is the process by which a molecule in an excited state drops to the ground state, resulting in the creation of a photon. ... Look up waveguide in Wiktionary, the free dictionary. ... 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. ... The optical spectrum (light or visible spectrum) is the portion of the electromagnetic spectrum that is visible to the human eye. ...


Naturally Occurring Photonic Crystals

A prominent example of a photonic crystal is the naturally occurring gemstone opal. Its play of colours is essentially a photonic crystal phenomenon based on Bragg diffraction of light on the crystal's lattice planes. Another well-known photonic crystal is found on the wings of some butterflies such as those of genus Morpho [1]. For other articles with similar names, see Opal (disambiguation). ... The Bragg formulation of X-ray diffraction (also referred to as Bragg diffraction) was first proposed by William Lawrence Bragg and William Henry Bragg in 1913 in response to their discovery that crystalline solids produced surprising patterns of reflected X-rays (in contrast to that of, say, a liquid). ... Species M. achilleana M. adonis Sunset Morpho, M. helena M. menelaus M. peleides White Morpho, … A Morpho butterfly may be one of over 80 described species of the genus Morpho. ...


History of Photonic Crystals

The simplest form of a photonic crystal is a one-dimensional periodic structure, such as a multilayer film (a Bragg mirror); electromagnetic wave propagation in such systems was first studied by Lord Rayleigh in 1887 [2], who showed that any such one-dimensional system has a band gap. One dimensional periodic systems continued to be studied extensively, and appeared in applications from reflective coatings where the reflection band corresponds to the photonic band gap and to distributed feedback (DFB) diode lasers where a crystallographic defect is inserted in the photonic band gap to define the laser wavelength. Two dimensional periodic optical structures, without band gaps, received limited study in the 1970s and 1980s. The possibility of two- and three-dimensionally periodic crystals with corresponding two- and three-dimensional band gaps was not suggested until 100 years after Rayleigh, by Eli Yablonovitch and Sajeev John in 1987 [3] [4], and such structures have since seen growing interest by a number of research groups around the world, with potential applications including LEDs, optical fiber, nanoscopic lasers, ultrawhite pigment, radio frequency antennas and reflectors, and photonic integrated circuits. Many research groups have recently succeeded in controlling the pace of light emission using photonic crystals[5]. In the process, they have verified the then 17-year old prediction of American physicist Eli Yablonovitch that ignited a world-wide rush to build tiny "chips" that control light beams. Researchers say it has many potential uses, not only as a tool for controlling quantum optical systems, but also in efficient miniature lasers for displays and telecommunications, in solar cells, and even in future quantum computers. It has been suggested that Optical coating be merged into this article or section. ... See also Rayleigh fading Rayleigh scattering Rayleigh number Rayleigh waves Rayleigh-Jeans law External links Nobel website bio of Rayleigh About John William Strutt MacTutor biography of Lord Rayleigh Categories: People stubs | 1842 births | 1919 deaths | Nobel Prize in Physics winners | Peers | British physicists | Discoverer of a chemical element ... 1887 (MDCCCLXXXVII) is a common year starting on Saturday (click on link for calendar) of the Gregorian calendar or a common year starting on Monday of the Julian calendar. ... This article or section does not adequately cite its references or sources. ... It has been suggested that Optical coating be merged into this article or section. ... 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. ... Crystalline solids have a very regular atomic structure: that is, the local positions of atoms with respect to each other are repeated at the atomic scale. ... The 1970s decade refers to the years from 1970 to 1979. ... This article does not cite any references or sources. ... Eli Yablonovitch along with Sajeev John, was one of the two physicists who invented the field of photonic crystals in 1987. ... Sajeev John is a “University Professor” at the University of Toronto and Government of Canada Research Chair holder. ... 1987 (MCMLXXXVII) was a common year starting on Thursday of the Gregorian calendar. ... External links LEd Category: TeX ... Optical fibers An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length by confining as much light as possible in a propagating form. ... An integrated circuit (IC) is a thin chip consisting of at least two interconnected semiconductor devices, mainly transistors, as well as passive components like resistors. ... This page is a list of sources of light. ... Eli Yablonovitch along with Sajeev John, was one of the two physicists who invented the field of photonic crystals in 1987. ... A solar cell, made from a monocrystalline silicon wafer A solar cell or photovoltaic cell is a device that converts light energy into electrical energy. ... The Bloch sphere is a representation of a qubit, the fundamental building block of quantum computers. ...


Fabrication Challenges

The major challenge for higher dimensional photonic crystals is in fabrication of these structures, with sufficient precision to prevent scattering losses blurring the crystal properties and with processes that can be robustly mass produced. One promising method of fabrication for two-dimensionally periodic photonic crystals is a photonic-crystal fiber, such as a "holey fiber". Using fiber draw techniques developed for communications fiber it meets these two requirements. For three dimensional photonic crystals various techniques [6] have been used including photolithography and etching techniques similar to those used for integrated circuits. To circumvent nanotechnological methods with their complex machinery, alternate approaches have been followed to grow photonic crystals as self-assembled structures from colloidal crystals. Photonic-crystal fiber (PCF), also spelled fibre, is a new class of optical fiber based on the properties of photonic crystals. ... Optical fibers An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length by confining as much light as possible in a propagating form. ... 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. ... An integrated circuit (IC) is a thin chip consisting of at least two interconnected semiconductor devices, mainly transistors, as well as passive components like resistors. ... Buckminsterfullerene C60, also known as the buckyball, is the simplest of the carbon structures known as fullerenes. ... In general, a colloid or colloidal dispersion is a substance with components of one or two phases, a type of mixture intermediate between a homogeneous mixture (also called a solution) and a heterogeneous mixture with properties also intermediate between the two. ...


Applications

Photonic crystals are attractive optical materials for controlling and manipulating the flow of light. One dimensional photonic crystals are already in widespread use in the form of thin-film optics with applications ranging from low and high reflection coatings on lenses and mirrors to colour changing paints and inks. Higher dimensional photonic crystals are of great interest for both fundamental and applied research, and the two dimensional ones are beginning to find commercial applications. The first commercial products involving two-dimensionally periodic photonic crystals are already available in the form of photonic-crystal fibers, which use a nanoscale structure to confine light with radically different characteristics compared to conventional optical fiber for applications in nonlinear devices and guiding exotic wavelengths. The three-dimensional counterparts are still far from commercialization but offer additional features possibly leading to new device concepts (e.g. optical computers), when some technological aspects such as manufacturability and principal difficulties such as disorder are under control. Thin-film optics is the branch of optics which deals with very thin structured layers of different materials. ... ChromaFlair is the registered trademark for a paint system, created by DuPont, which appears to change colour depending on the light source and viewing angle. ... Security printing is the field of the printing industry that deals with the printing of items such as banknotes, passports, stock certificates, postage stamps and identity cards. ... Photonic-crystal fiber (PCF), also spelled fibre, is a new class of optical fiber based on the properties of photonic crystals. ... Optical fibers An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length by confining as much light as possible in a propagating form. ... An optical computer is a computer that uses light instead of electricity (i. ...


See also

Photonic-crystal fiber (PCF), also spelled fibre, is a new class of optical fiber based on the properties of photonic crystals. ... Thin-film optics is the branch of optics which deals with very thin structured layers of different materials. ...

References

  1. ^ S. Kinoshita, S. Yoshioka and K. Kawagoe “Mechanisms of structural colour in the Morpho butterfly: cooperation of regularity and irregularity in an iridescent scale” Proc. R. Soc. Lond. B 269, 1417-1421 (2002) http://lib.store.yahoo.net/lib/buginabox/kinoshita.pdf
  2. ^ J. W. S. Rayleigh, "On the remarkable phenomenon of crystalline reflexion described by Prof. Stokes." Phil. Mag. 26, 256-265. (1888)
  3. ^ E. Yablonovitch "Inhibited Spontaneous Emission in Solid-State Physics and Electronics", Phys. Rev. Lett., Vol. 58, 2059 (1987) http://www.ee.ucla.edu/faculty/papers/eliy1987PhysRevLett.pdf
  4. ^ S. John, "Strong Localization of Photons in Certain Disordered Dielectric Superlattices", Phys. Rev. Lett. 58, 2486 (1987) http://www.physics.utoronto.ca/~john/john/p2486_1.pdf
  5. ^ P. Lodahl, A.F. van Driel, I.S. Nikolaev, A. Irman, K. Overgaag, D. Vanmaekelbergh, and W.L. Vos "Controlling the dynamics of spontaneous emission from quantum dots by photonic crystals" Nature 430, 654 - 657 (2004) http://cops.tnw.utwente.nl/pdf/04/nature02772.pdf
  6. ^ Review: S.Johnson (MIT) Lecture 3: Fabrication technologies for 3d photonic crystals, a survey http://ab-initio.mit.edu/photons/tutorial/L3-fab.pdf

External links

  • Photonic Crystal Article in Scientific American by Eli Yablonovitch [1]
  • Yuri A. Vlasov's Collection of Photonic Band Gap Research Links [2]
  • Prof Yablonovitch's Optoelectronics Group at UCLA School of Engineering and Applied Sciences [3].
  • Prof John's page at University of Toronto [4].
  • Prof Vos's group at University of Twente www.photonicbandgaps.com
  • Photonic crystals tutorials by Prof S. Johnson at MIT [5]
  • Autocloning at Photonic Lattice, Inc [6].
  • ePIXnet Nanostructuring Platform for Photonic Integration

  Results from FactBites:
 
Photonic Crystal Research (613 words)
Photonic crystals are periodic dielectric structures that have a band gap that forbids propagation of a certain frequency range of light.
Photonic crystals are described exactly by Maxwell's Equations, which we can (and do) solve by the application of massive computational power.
Photonic Micropolis: This is not a research project, but is simply a fanciful depiction of a "photonic micropolis" incorporating many elements of our research.
  More results at FactBites »

 
 

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