Encyclopedia

Optical axis In an optical system, the optical axis is an imaginary line that defines the path along which light propagates through the system. For a system composed of simple lenses and mirrors, the axis passes through the center of curvature of each surface, i.
Optical axis gratings Optical axis gratings (OAGs) are gratings of optical axis of a birefringent material. In OAGs, the birefringence of the material is constant, while the direction of optical axis is periodically modulated in a fixed direction.
Optical beam induced current Optical beam induced current (OBIC) is a semiconductor analysis technique performed using laser signal injection. The technique induces the creation of electron–hole pairs in the semiconductor sample through the use of the microscope's laser source.
Optical brightener Optical brighteners, optical brightening agents, fluorescent brightening agents or fluorescent whitening agents (FWAs) are dyes that absorb light in the ultraviolet and violet region of the electromagnetic spectrum, and re-emit light in the blue region. These additives are designed to enhance the appearance of colours in fabrics and on papers.
Optical buffer In telecommunications, an optical buffer is a device that is capable of temporarily storing light. Just as in the case of a regular buffer, it is a storage medium that enables compensation for a difference in time of occurrence of events.
Optical Black Hole An optical black hole is a type of artificially produced phenomenon in which light is slowed significantly by passing it through an ultra-low temperature Bose-Einstein condensate that is itself spinning faster than the speed of light within to create a vortex capable of trapping the light behind an event horizon just as would an astronomical black hole.
Optical Burst Switching Optical Burst Switching (OBS) is an experimental switching paradigm representing an intermediate solution between circuit (wavelength) and packet switching in optical networks. Its purpose is to dynamically provision sub-wavelength granularity by optimally combining electronics and optics.
Optical cavity An optical cavity or optical resonator is an arrangement of mirrors that forms a standing wave cavity resonator for light waves. Optical cavities are a major component of lasers, surrounding the gain medium and providing feedback of the laser light.
Optical coating An optical coating is a thin layer of material placed on an optical component such as a lens or mirror which alters the way in which the optic reflects and transmits light. One type of optical coating is an antireflection coating, which reduces unwanted reflections from surfaces, and is commonly used on spectacle and photographic lenses.
Optical coherence tomography Optical coherence tomography (OCT) is an interferometric, non-invasive optical tomographic imaging technique offering millimeter penetration (approximately 2--3 mm in tissue) with sub-micrometre axial and lateral resolution. The technique was first demonstrated in 1991 with ~30µm axial resolution.
Optical communications repeater An optical communications repeater is used in a fiber-optic communications system to regenerate an optical signal by converting it to an electrical signal, processing that electrical signal and then retransmitting an optical signal. Such repeaters are used to extend the reach of optical communications links by overcoming loss due to attenuation of the optical fibre and distortion of the optical signal.
Optical Carrier Optical Carrier levels describe a range of digital signals that can be carried on SONET fiber optic network.IEC online study material, SONET introduction The number in the Optical Carrier level is directly proportional to the data rate of the bitstream carried by the digital signal.
Optical disc In computing, sound reproduction, and video, an optical disc is a flat, circular, usually polycarbonate disc whereon data is stored in the form of pits (or bumps) within a flat surface, usually along a single spiral groove that covers the entire recorded surface of the disc. This data is generally accessed when a special material on the disc (often aluminum) is illuminated with a laser diode.
Optical disc packaging Optical disc packaging is the packaging that accompanies CDs, DVDs, and other formats of optical media. As a general rule, most such packaging is rigid or semi-rigid and designed to protect the media from scratches and other types of exposure damage.
Optical disc recorder A CD recorder, CD writer or CD burner is a compact disc drive that can be used to produce discs readable in other CD-ROM drives and audio CD players. A DVD recorder produces DVD discs playable in stand-alone video players or DVD-ROM drives.
Optical disk library An Optical disk library is a form of tertiary storage (although sometimes offline as used in disaster recovery situations) in which many optical discs (such as DVDs) are stored in a "jukebox" configuration. Before the advent of the modern SAN and much cheaper hard disks, large-volume storage on DVD was more price-efficient than magnetic media.
Optical fiber An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length by total internal reflection. Fiber optics is the branch of applied science and engineering concerned with such optical fibers.
Optical fiber composite overhead ground wire Optical fiber composite overhead ground wire (OPGW) is a type of cable that is used in the construction of electric power transmission and distribution lines. Such cable combines the functions of grounding and communications.
Optical fiber connector An optical fiber connector constitutes a fiber-to-fiber interconnection and aligns the fiber core of two optical fibers. Due to the fast development of optical nets, a variety of optical fiber connectors are available.
Optical field The optical field is a term used in physics and vector calculus to designate the electric field shown as E in the electromagnetic wave equation which can be derived from Maxwell's Equations. In electromagnetic theory, the electromagnetic wave propagates because the longitudinal waves of the magnetic field oscillate in the same direction as the direction of propagation, while transverse waves of the electrical field oscillate in a direction perpendicular to the direction of propagation.
Optical flat Optical flats are optical-grade glass structures lapped and polished to be extremely flat on one or both sides. They are used with a monochromatic light to determine the flatness of other optical surfaces by interference.
Optical frequency multiplier An optical frequency multiplier is a nonlinear optical device, in which photons interacting with a nonlinear material are effectively "combined" to form new photons with greater energy, and thus higher frequency (and shorter wavelength). Two types of devices are currently common, frequency doublers often based on lithium niobate, potassium titanyl phosphate (KTP) or lithium triborate (LBO), and frequency triplers typically made of potassium dihydrogen phosphate (PTP) or KTP.
Optical Gravitational Lensing Experiment The Optical Gravitational Lensing Experiment is a Polish astronomy project based at Warsaw University that is chiefly concerned with discovering dark matter using the microlensing technique. Since the project began in 1992, it has discovered several extrasolar planets as a side benefit.
Optical hybrid A 90° optical hybrid is a six-port device that is used for coherent signal demodulation for either homodyne or heterodyne detection. It would mix the incoming signal with the four quadratural states associated with the reference signal in the complex-field space.
Optical character recognition Optical character recognition, usually abbreviated to OCR, is a type of computer software designed to translate images of handwritten or typewritten text (usually captured by a scanner) into machine-editable text, or to translate pictures of characters into a standard encoding scheme representing them (e.g.
Optical chopper An optical chopper is a mechanical device which periodically interrupts a light beam. Three types are available: variable frequency rotating disc choppers, fixed frequency tuning fork choppers, and optical shutters.
Optical illusion An optical illusion is characterized by visually perceived images that, at least in common sense terms, are deceptive or misleading. Therefore, the information gathered by the eye is processed by the brain to give, on the face of it, a percept that does not tally with a physical measurement of the stimulus source.
Optical imaging Optical imaging is a recent technique that gives cognitive neuroscientists the ability to simultaneously obtain information about the source of neural activity as well as its time course. In other words, it allows them to "see" neural activity and study the functioning of the brain.
Optical interleaver An optical interleaver is a 3-port passive fiber-optic device that is used to combine two sets of dense wavelength-division multiplexing (DWDM) channels (odd and even channels) into a composite signal stream in an interleaving way. For example, optical interleaver takes two multiplexed signals with 100 GHz spacing and interleaves them, creating a denser DWDM signal with channels spaced 50 GHz apart.
Optical Internetworking Forum The Optical Internetworking Forum (OIF) was organized to facilitate and accelerate the development of next-generation optical internetworking products. The OIF produces Electrical, Tunable Laser, Very Short Reach Hardware Interfaces.
Optical jukebox An optical jukebox An optical jukebox is a robotic storage device that can automatically load and unload optical media, such as Ultra Density Optical or Blu-ray disc and provide terabytes of near-line information. The devices are often called optical disk libraries, robotic drives, or autochangers.
Optical lattice An optical lattice is formed by using counterpropagating laser beams to create a periodic (in space) intensity pattern. The resulting periodic potential can then be used to trap neutral atoms via the Stark shift.
Optical lens design Optical lens design is the science/art of calculating the various lens construction parameters (variables) that will meet or at least approach desired performance requirements while staying within required constraint values, and any cost/schedule limitations.
Optical link An optical link is a communications link that consists of a single end-to-end optical circuit. A piece of fiber optic cable, or a concatenation of fiber optic cables to make a dark fiber link, is the simplest form of optical link.
Optical mark recognition Optical mark recognition is the process of capturing data by contrasting reflectivity at predetermined positions on a page. By shining a beam of light onto the document the scanner is able to detect a marked area because it is more reflective than an unmarked surface.
Optical microcavity An optical microcavity is a structure formed by reflecting faces on the two sides of a spacer layer or optical medium. The name microcavity stems from the fact that it is often only a few micrometers thick, the spacer layer sometimes even in the nanometer range.
Optical mineralogy Optical mineralogy is the study of minerals by measuring their optical properties. Most commonly, rock and mineral samples are prepared as thin sections or grain mounts for study in the laboratory with a petrographic microscope.
Optical motion tracking Motion Tracking can differ from Motion Capture because in applications such as sports and missiles the object of interest is tracked optically instead of a person. The technology is basically the same, with some differences in that many of the Optical Motion Tracking applications occur outdoors, requiring differing lens and camera configurations.
Optical mount An optical mount is a device used to join a normal camera and another optical instrument, such as a microscope or telescope. The optical mount is generally attached to the camera as a lens would on one end, and fastened to the other instrument in a similar fashion.
Optical neural network An optical neural network is an implementation of a neural network model with optical components. One possibility is the Hopfield neural networkfor optical neural technologies (Russian Academy of Sciences): http://www.
Optical parametric oscillator An optical parametric oscillator (OPO) is an parametric oscillator which oscillates at optical frequencies. It converts an input laser wave (called "pump") into two output waves of lower frequency (omega_s, omega_i) by means of nonlinear optical interaction.
Optical path length In optics, optical path length (OPL) is the product of the geometric length of the path light follows through the system, and the index of refraction of the medium through which it propagates. A difference in optical path length between two paths is often called the optical path difference (OPD).
Optical performance monitoring Optical performance monitoring (OPM) is used for managing high capacity dense wavelength division multiplexing (DWDM) optical transmission and switching systems in Next Generation Networks (NGN). OPM involves assessing the quality of data channel by measuring its optical characteristics without directly looking at the transmitted sequence of bits.
Optical physics Optical physics, or optical science, is a subfield of atomic, molecular, and optical physics. It is the study of the generation of electromagnetic radiation, the properties of that radiation, and the interaction of that radiation with matter, especially its manipulation and control.
Optical power budget The optical power budget, in a fiber-optic communication link, refers to the allocation of available optical power (launched into a given fiber by a given source) among various loss-producing mechanisms such as launch coupling loss, fiber attenuation, splice losses, and connector losses, in order to ensure that adequate signal strength (optical power) is available at the receiver.
Optical power margin Optical power margin: In an optical communications link, the difference between (a) the optical power that is launched by a given transmitter into the fiber, less transmission losses from all causes, and (b) the minimum optical power that is required by the receiver for a specified level of performance.
Optical proximity correction Optical proximity correction (OPC) is a photolithography enhancement technique commonly used to compensate for image errors due to diffraction or process effects. The two most common applications for OPC are linewidth differences between features in regions of different density (e.
Optical pumping Optical pumping is a process in which light is used to raise (or "pump") electrons from a lower energy level in an atom or molecule to a higher one. It is commonly used in laser construction, to pump the active laser medium so as to achieve population inversion.
Optical return loss In fiber optics and telecommunications, optical return loss is the ratio of the optical power arriving at an interface to the optical power reflected back from the same interface. It is usually expressed in decibels.
Optical ring resonators Optical ring resonators consist of a waveguide in a closed loop coupled to one or more input/output (or bus) waveguides. When light of the appropriate wavelength is coupled to the loop by the input waveguide, it builds up in intensity over multiple round-trips due to constructive interference.
Optical rotation Optical rotation or optical activity is the rotation of linearly polarized light as it travels through certain materials. It occurs in solutions of chiral molecules such as sucrose (sugar), solids with rotated crystal planes such as quartz, and spin-polarized gases of atoms or molecules.
Optical rotatory dispersion Optical rotatory dispersion is the variation in the optical rotation of a substance with a change in the wavelength of light. Optical rotatory dispersion can be used to find the absolute configuration of metal complexes.
Optical scalars In general relativity, optical scalars are a set of scalars that describe various properties of null geodesic congruences. The three optical scalars used in general relativity are expansion, shear and twist (vorticity) and were first defined and used by Sachs (1961).
Optical Society of America The Optical Society of America (OSA) is a scientific society dedicated to advancing the study of light—optics and photonics—in theory and application, by means of worldwide research, scientific publishing, conferences and exhibitions, partnership with industry, and the education of new generations of scientists. The organization's members reside in over 100 nations and span many disciplines: physicists, biologists, medical researchers, electrical engineers, display component engineers, communications specialists, vision scientists, astronomers, meteorologists, materials scientists, and technical specialists in imaging, to name just a few.
Optical Storage Technology Association The Optical Storage Technology Association (OSTA) is an international trade association which promotes the use of recordable optical technologies and products. Representing more than 85 percent of worldwide writable optical product shipment's manufacturers and resellers, it was incorporated in 1992.
Optical tape Optical tape refers to a tape used for computer data storage, similar to magnetic tape, but using optical instead of magnetic means of storage. They provide the possibility of far greater storage capacities than either magnetic tape or optical discs.
Optical thickness Optical thickness is the depth of a material or medium in which the intensity of light (or other radiation) of a given frequency is reduced by a factor of 1/e. In rough terms â…” of the light is absorbed within one optical thickness depth.
Optical tomography Optical tomography is a form of computed tomography that creates a digital volumetric model of an object by reconstructing images made from light transmitted and scattered through an object. Optical tomography is used mostly as a form of medical imaging.
Optical transfer function The Optical Transfer Function (OTF) describes the spatial (angular) variation as a function of spatial (angular) frequency. When the image is projected onto a flat plane, such as photographic film or a solid state detector, spatial frequency is the preferred domain, but when the image is referred to the lens alone, angular frequency is preferred.
Optical turnstile An optical turnstile is a physical security device designed to restrict or control access to a building or secure area. Optical turnstile are usually a part of an access control system, which also consists of software, card readers, and controllers.
Optical tweezers An optical tweezer is a scientific instrument that uses a focused laser beam to provide an attractive force (typically on the order of piconewtons) to physically hold and move microscopic dielectric objects. Optical tweezers have been particularly successful in studying a variety of biological systems in recent years.
Optical Transport Network ITU-T defines Optical Transport Network (OTN) as a composed of a set of Optical Network Elements connected by optical fibre links, able to provide functionality of transport, multiplexing, routing, management, supervision and survivability of optical channels carrying client signals. full ITU-T OTN definitions
Optical vortex An optical vortex (also known as a screw dislocation or phase singularity) is a zero of an optical field, a point of zero intensity. Research into the properties of vortices has thrived since a comprehensive paper by Nye and Berry, in 1974, described the basic properties of 'dislocations in wave trains'.
Optical window In astronomy, the optical window is that portion of the electromagnetic spectrum that passes through the atmosphere all the way to the ground. Most EM energy never makes it through the atmosphere, so this is like a window that lets in just a little of what is out there.
Opticks Opticks is a book written by English physicist Isaac Newton that was released to the public in 1704. It is about optics and the refraction of light, and is considered one of the great works of science in history.
Opticution Opticution is the term given to the damaging beyond viability of biological samples that are manipulated via optical traps, most commonly optical tweezers. The term was coined by Arthur Ashkin, who developed optical tweezers at Bell Labs in the 1970s and 80s.
Optigan The Optigan (a portmanteau of Optical Organ) was an early electronic keyboard instrument designed for the consumer market. It is best remembered today for its reputation of frequent failure and its kitschy appearance and sound.
Optiganally Yours Optiganally Yours is a band formed around the Optigan, a toy organ produced by Mattel in the 1970s that plays the sounds of instruments that have been recorded onto celluloid disks. Pea Hix wanted to form an Optigan-based cover band, but teamed up with Rob Crow to begin writing original songs for the Optigan.
Optile Optile (Organisation Professionnelle des Transports d'ĂŽle-de-France, or Professional Transport Organisation of ĂŽle-de-France) is a public transport organisation, created in October 2000 from a merger between several private bus companies serving suburban Paris. It regulates bus routes under the authority of STIF, the Parisian transport authority.
Optimal Asymmetric Encryption Padding In cryptography, Optimal Asymmetric Encryption Padding (OAEP) is a padding scheme often used together with RSA encryption. The OAEP algorithm is a form of feistel network which uses a pair of random oracles G and H to process the plaintext prior to asymmetric encryption.
Optimal foraging theory A central concern of ecology has traditionally been foraging behavior. In its most basic form, optimal foraging theory states that organisms focus on consuming the most energy while expending the least amount of energy.
Optimal maintenance Optimal maintenance is the discipline within operations research concerned with maintaining a system in a manner that maximizes profit or minimizes cost. Cost functions depending on the reliability and maintainability characteristics of the system of interest determine the parameters to minimize.
Optimal stopping The theory of optimal stopping is concerned with the problem of choosing a time to take a particular action, in order to maximise an expected reward or minimise an expected cost. Optimal stopping problems can be found in areas of Statistics.
Optimal substructure In computer science, a problem is said to have optimal substructure if its optimal solution can be constructed efficiently from optimal solutions to its subproblems. This property is used to determine the usefulness of dynamic programming and greedy algorithms in a problem.
Optimal tax Optimal tax theory is the study of how best to design a tax to avoid distortion and inefficiency. Other things being equal, if a tax-payer must choose between two mutually exclusive economic projects (say investments) that face the same pre-tax risk and returns, the one with the lower tax or with a tax break would be chosen by the rational actor.
Optimates Optimates (singular optimas, The Best of Men, Italian: ottimati; also known as the boni, The Good Men) were the traditionalist faction of the later Roman Republic. They wished to limit the power of the popular assemblies and the Tribunes of the Plebs, and to extend the power to the Senate, which was viewed as more stable and more dedicated to the well-being of Rome.
Optimax V-Power is the brand name given to Shell's super-premium petrol (gasoline), formerly known as Optimax in some regions. It usually has a much higher octane rating than standard petrol at around RON (Research Octane Rating) 98; however this varies by market: In the UK, V-Power has a rating of 99 RON, while in the Republic of Ireland it is rated at 95 RON.
Optime At the University of Cambridge in England, an optime is a student who graduates with a second-class (Senior Optime) or third-class (Junior Optime) honours mathematics degree. An example of a noted alumnus who is an Optime is Luke Pebody.
Optimism bias Optimism bias is the demonstrated systematic tendency for people to be over-optimistic about the outcome of planned actions. People tend to see the future through "rose-colored glasses," as the saying goes.
Optimist International Optimist International is a service club organization aimed at providing hope and positive vision for children in communities throughout the world. The first Optimist Club was founded in 1911 in Buffalo, New York and the international organization was founded in 1919 in Louisville, Kentucky.
Optimistic concurrency control In computer science, in the field of databases, optimistic concurrency control, (OCC) is a concurrency control method used in relational databases without using locking. It is commonly referred to as optimistic locking, a misnomer.
Optimists Cricket Club The Optimists Cricket Club, known simply as the Optimists or abbreviated to OCC, is a cricket club based in Walferdange, in central Luxembourg. The Optimists are the dominant club in Luxembourg, and serve as an auxiliary governing body for cricket in the Grand Duchy, alongside the Luxembourg Cricket Federation.
Optimization (computer science) In computing, optimization is the process of modifying a system to make some aspect of it work more efficiently or use less resources. For instance, a computer program may be optimized so that it executes more rapidly, or is capable of operating within a reduced amount of memory storage, or draws less battery power in a portable computer.
Optimization (mathematics) In mathematics, the term optimization, or mathematical programming, refers to the study of problems in which one seeks to minimize or maximize a real function by systematically choosing the values of real or integer variables from within an allowed set. This problem can be represented in the following way
Optimize (magazine) Optimize is a magazine whose intended reader is a corporate officer; according to BPA International (as cited in "Media Kit 2004" listed in the "References" section), seventy per cent of Optimize's readers are Chief Information Officers, Chief Technology Officers, or Vice Presidents of information systems, while the remaining thirty per cent are "technology-involved" corporate officers. Brian Gillooly is the founding and, as of 27 March 2004, current editor-in-chief of Optimize.
Optimized Link State Routing protocol The Optimized Link State Routing (OLSR) protocol is a protocol to connect mobile ad-hoc networks, sometimes called wireless mesh networks. It is a link-state routing protocol that collects data about available networks and then calculates an optimized routing table.
Optimized Power Control Optimized Power Control, shortened as OPC, is a function of a CD or DVD writer. It checks the proper writing power and reflection of the media in use, calculating the optimum laser power and adjusting it for writing the particular session.
Optimized Systems Software Optimized Systems Software (OSS) was a small company producing operating systems and programming languages for the Atari 8-bit and Apple II computer families. OSS is most noted for authoring Atari's BASIC and Disk Operating System (DOS) products.
Optimo Optimo (Espacio) is the name of a long-running (since 1997), infamous Sunday-night club based in Glasgow, Scotland at the Sub Club on Jamaica Street. Often known simply as 'Optimo', it takes its name from the eponymous Liquid Liquid song and 1983 EP title.
Optimum "L" filter The Optimum "L" filter (also known as a Legendre filter) was proposed by Athanasios Papoulis in 1958. It has the maximum roll off rate for a given filter order while maintaining a monotonic frequency response.
Optimum currency area In economics, an optimum currency area (OCA), also known as an optimal currency region (OCR), is a geographical region in which it would maximize economic efficiency to have the entire region share a single currency. It describes the optimal characteristics for the merger of currencies or the creation of a new currency.
Optimum productions Optimum Productions is a Marketing and Event Services company. A New York based corporation, Optimum Productions is the parent company of OP Digital, a marketing and web design firm, and OP Events, an entertainment and event planning firm.
Optimum programming In the history of computing, optimum programming is the practice of arranging a computer program's instructions in memory so as to minimize the time the machine spends waiting for instructions. It is of historical interest mainly, due to the design of many early digital computers.
Optimum Population Trust The Optimum Population Trust is a registered charity, small think tank and campaign group concerned with the impact of population growth on the natural environment. With respect to population growth, it researches climate change, energy requirements, biodiversity and other environmental factors.
Optimum Releasing Optimum Releasing is a film distributor company working in the UK The company releases many films, especially foreign language films, but is perhaps best known for its anime releases, including the contract to release all Studio Ghibli films in the UK.
Optimum TV Optimum TV is a cable service from Cablevision that uses a fiber optic network. This service is becoming dated and less popular, due to Cablevision's new iO digital cable service, which offers many more features and better picture quality.
Optimum Wound Profile Optimum Wound Profile were an industrial metal band from Ipswich, UK, active between the years 1991-1996. Combining elements of metal, crust punk, and sampling/programming technologies they were very prolific for such a short lived band.
Optimus Design Systems Optimus Design Systems (ODS) was a small publisher of role-playing games, based in Buffalo, New York. The company produced two products, the Battlelords of the 23rd Century science-fiction role-playing game, and the Blood Dawn post-apocalyptic RPG.
Optimus Primal Optimus Primal (Convoy or Convobat in Japan, later Beast Convoy to differentiate him from the original Convoy, Blackjack in some European markets) is a fictional character from the Transformers toyline, and the leader of the Maximal forces and the main protagonist in the Beast Wars television series.
Optimus Prime Optimus Prime is a fictional commander of the heroic Autobots and the main protagonist from the Transformers Universes. His name is iconic, and has since been reused for alternate universe versions of the character who have appeared in more recent Transformers media.

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