A photonic crystal is an optical nanostructure in which the refractive index changes periodically. This affects the propagation of light in the same way that the structure of natural crystals gives rise to X-ray diffraction and that the atomic lattices of semiconductors affect their conductivity of electrons. Photonic crystals occur in nature in the form of structural coloration and animal reflectors, and, as artificially produced, promise to be useful in a range of applications.
Photonic-crystal fiber (PCF) is a class of optical fiber based on the properties of photonic crystals. It was first explored in 1996 at University of Bath, UK. Because of its ability to confine light in hollow cores or with confinement characteristics not possible in conventional optical fiber, PCF is now finding applications in fiber-optic communications, fiber lasers, nonlinear devices, high-power transmission, highly sensitive gas sensors, and other areas. More specific categories of PCF include photonic-bandgap fiber, holey fiber, hole-assisted fiber, and Bragg fiber. Photonic crystal fibers may be considered a subgroup of a more general class of microstructured optical fibers, where light is guided by structural modifications, and not only by refractive index differences.
Sir David Neil Payne CBE FRS FREng is a British professor of photonics who is director of the Optoelectronics Research Centre at the University of Southampton. He has made several contributions in areas of optical fibre communications over the last fifty years and his work has affected telecommunications and laser technology. Payne’s work spans diverse areas of photonics, from telecommunications and optical sensors to nanophotonics and optical materials, including the introduction of the first optical fibre drawing tower in a university.
An optical waveguide is a physical structure that guides electromagnetic waves in the optical spectrum. Common types of optical waveguides include optical fiber waveguides, transparent dielectric waveguides made of plastic and glass, liquid light guides, and liquid waveguides.
Philip St. John Russell, FRS, is a Director of the Max Planck Institute for the Science of Light in Erlangen, Germany. His area of research is "photonics and new materials".
A fiber laser is a laser in which the active gain medium is an optical fiber doped with rare-earth elements such as erbium, ytterbium, neodymium, dysprosium, praseodymium, thulium and holmium. They are related to doped fiber amplifiers, which provide light amplification without lasing. Fiber nonlinearities, such as stimulated Raman scattering or four-wave mixing can also provide gain and thus serve as gain media for a fiber laser.
Silicon photonics is the study and application of photonic systems which use silicon as an optical medium. The silicon is usually patterned with sub-micrometre precision, into microphotonic components. These operate in the infrared, most commonly at the 1.55 micrometre wavelength used by most fiber optic telecommunication systems. The silicon typically lies on top of a layer of silica in what is known as silicon on insulator (SOI).
In optics, a supercontinuum is formed when a collection of nonlinear processes act together upon a pump beam in order to cause severe spectral broadening of the original pump beam, for example using a microstructured optical fiber. The result is a smooth spectral continuum. There is no consensus on how much broadening constitutes a supercontinuum; however researchers have published work claiming as little as 60 nm of broadening as a supercontinuum. There is also no agreement on the spectral flatness required to define the bandwidth of the source, with authors using anything from 5 dB to 40 dB or more. In addition the term supercontinuum itself did not gain widespread acceptance until this century, with many authors using alternative phrases to describe their continua during the 1970s, 1980s and 1990s.
A subwavelength-diameter optical fibre is an optical fibre whose diameter is less than the wavelength of the light being propagated through it. An SDF usually consists of long thick parts at both ends, transition regions (tapers) where the fibre diameter gradually decreases down to the subwavelength value, and a subwavelength-diameter waist, which is the main acting part. Due to such a strong geometrical confinement, the guided electromagnetic field in an SDF is restricted to a single mode called fundamental.
Optofluidics is a research and technology area that combines the advantages of fluidics and optics. Applications of the technology include displays, biosensors, lab-on-chip devices, lenses, and molecular imaging tools and energy.
Benjamin John Eggleton FAA, FTSE, FOSA, FIEEE is the Director of The University of Sydney Nano Institute. He also currently serves as Co-Director of the NSW Smart Sensing Network (NSSN).
Microstructured optical fibers (MOF) are optical fiber waveguides where guiding is obtained through manipulation of waveguide structure rather than its index of refraction.
In physics, a high contrast grating is a single layer near-wavelength grating physical structure where the grating material has a large contrast in index of refraction with its surroundings. The term near-wavelength refers to the grating period, which has a value between one optical wavelength in the grating material and that in its surrounding materials.
Optical rogue waves are rare pulses of light analogous to rogue or freak ocean waves. The term optical rogue waves was coined to describe rare pulses of broadband light arising during the process of supercontinuum generation—a noise-sensitive nonlinear process in which extremely broadband radiation is generated from a narrowband input waveform—in nonlinear optical fiber. In this context, optical rogue waves are characterized by an anomalous surplus in energy at particular wavelengths or an unexpected peak power. These anomalous events have been shown to follow heavy-tailed statistics, also known as L-shaped statistics, fat-tailed statistics, or extreme-value statistics. These probability distributions are characterized by long tails: large outliers occur rarely, yet much more frequently than expected from Gaussian statistics and intuition. Such distributions also describe the probabilities of freak ocean waves and various phenomena in both the man-made and natural worlds. Despite their infrequency, rare events wield significant influence in many systems. Aside from the statistical similarities, light waves traveling in optical fibers are known to obey the similar mathematics as water waves traveling in the open ocean, supporting the analogy between oceanic rogue waves and their optical counterparts. More generally, research has exposed a number of different analogies between extreme events in optics and hydrodynamic systems. A key practical difference is that most optical experiments can be done with a table-top apparatus, offer a high degree of experimental control, and allow data to be acquired extremely rapidly. Consequently, optical rogue waves are attractive for experimental and theoretical research and have become a highly studied phenomenon. The particulars of the analogy between extreme waves in optics and hydrodynamics may vary depending on the context, but the existence of rare events and extreme statistics in wave-related phenomena are common ground.
Prof. Ravindra Kumar Sinha is the Vice Chancellor of Gautam Buddha University, Greater Noida, Gautam Budh Nagar Under UP Government. He was the director of the CSIR-Central Scientific Instruments Organisation (CSIR-CSIO) Sector-30C, Chandigarh-160 030, India. He has been a Professor - Applied Physics, Dean-Academic [UG] & Chief Coordinator: TIFAC-Center of Relevance and Excellence in Fiber Optics and Optical Communication, Mission REACH Program, Technology Vision-2020, Govt. of India Delhi Technological University Bawana Road, Delhi-110042, India.
(James) Roy Taylor is Professor of Ultrafast Physics and Technology at Imperial College London.
David John Richardson is a Professor and Deputy Director of the Optoelectronics Research Centre at the University of Southampton.
Arti Agrawal is a scientist and engineer known for her work on computational photonics as well as diversity, equity, and inclusion in STEM; she has been recognized in both of these areas by a number of awards. Her research is focused on numerical modeling and simulation of photonic devices and optical components. Agrawal is currently serving as Associate Professor and the Director of Women in Engineering and Information Technology at the University of Technology Sydney and Associate Vice President of Diversity for the IEEE Photonics Society.
Luc Thévenaz is a Swiss physicist who specializes in fibre optics. He is a professor of physics at EPFL and the head of the Group for Fibre Optics School of Engineering.
Alexander Luis Gaeta is an American physicist and the David M. Rickey Professor of Applied Physics at Columbia University. He is known for his work on quantum and nonlinear photonics. He is a Fellow of the American Physical Society, Optica, and of the Institute of Electrical and Electronics Engineers.
