Photonics Dictionary

A vision defect commonly referred to as nearsightedness. The defective condition results when the image of a distant object is focused in front of the retina by the relaxed eye. It can be corrected...

A ghost image that has the reverse lightness relations of the original image. This phenomenon is a common optical illusion that takes place in the human visual system, following long exposures to an...

Glass containing small quantities of neodymium oxide that is used as a filter plate in color television or as a lasing medium (Nd:glass) in solid-state lasers.

The nondestructive analysis and recording of industrial components based on the absorption of relatively low-energy neutrons by material having low atomic numbers. The visible image formed by the...

The use of retroreflective projection technology (RPT) to project a background image onto a masked object, such as a vehicle or overcoat, thereby making the masked object appear invisible....

An optical channel monitor (OCM) is a device used in optical communication systems to monitor and analyze the performance of individual channels within a wavelength-division multiplexing (WDM)...

Optical fiber is a thin, flexible, transparent strand or filament made of glass or plastic used for transmitting light signals over long distances with minimal loss of signal quality. It serves as a...

Optical switching refers to the process of controlling the routing or transmission of optical signals within a network using various techniques to selectively switch or redirect optical paths. This...

A fundamental law of wave scattering theory that connects the extinction cross section of a scatterer to the real part of the forward-scattering amplitude. It is used in the study of division of...

Optics is the branch of physics that studies the behavior and properties of light, including its interactions with matter and its manifestation as both particle and wave phenomena. It encompasses the...

An organic light-emitting diode (OLED) is a type of light-emitting diode (LED) technology that utilizes organic compounds to produce light. OLEDs are commonly used in display technologies, such as...

A television camera tube in which a low-velocity electron beam scans a photoactive mosaic that has been created by an optical image. Once scanned by the electron beam, the electrical storage capacity...

Opsins are a group of light-sensitive proteins found primarily in the retinas of vertebrate and invertebrate eyes, as well as in other light-sensitive tissues. These proteins play a crucial role in...

In interlaced television scanning, an effect in which the lines of one field fail to fall exactly within the lines of the following field, both fields comprising one frame of the picture. The lines...

Photocathodes are specialized materials or surfaces that exhibit the photoelectric effect, wherein the absorption of photons leads to the emission of electrons. When photons with sufficient energy...

A photomultiplier tube (PMT) is a highly sensitive vacuum tube that detects and amplifies low levels of light. It is widely used in various applications where high sensitivity, fast response times,...

A surgical procedure for correcting vision by reshaping the outer surface of the cornea through the use of a laser system.

Phototherapy is a medical treatment that involves the use of light to treat various conditions, particularly those related to the skin or mood disorders. There are different types of phototherapies,...

A kinescope used to survey the details of television video transmission.

A term referring to the cathode-ray tube used in television receivers.

A pixel, short for "picture element," is the smallest controllable element of a digital image or display. It is a fundamental unit that represents a single point in a raster image, which is a grid of...

A subsurface imaging technique based upon the polarization of light reflected off an object. The polarization of reflected light gives information about the object's absorption properties that...

A set of three colored lights which, when mixed, give the sensation of white light. The set used in color television, for example, is red, green, blue (RGB).

Quantitative phase imaging (QPI) is an advanced imaging technique used in microscopy to measure and analyze the optical phase information of transparent specimens. Unlike traditional brightfield...

Quantum dot light-emitting diode (QLED) is a display technology that utilizes quantum dots, which are semiconductor nanocrystals, to produce vibrant and high-quality images. QLED displays are...

Having properties resembling those of light- waves; e.g., the propagation of waves in the television spectrum.

The frequency range for radio and television transmission.

Rare-earth elements (REEs) are a group of seventeen chemical elements found in the Earth's crust, characterized by their unique properties and scarcity relative to other elements. Despite their name,...

Raster scanning is a technique used in imaging and scanning systems to systematically capture and process information from a two-dimensional area or surface. It involves moving a sensor or scanning...

The ability of a vision system to interpret an image in a short enough time to keep pace with most operations.

Also known as display primaries. Colors formed by a television receiver that are of constant chromaticity and variable luminance, and that, mixed in certain proportions, form other colors. Red, green...

A reconfigurable optical add-drop multiplexer (ROADM) is a key component in wavelength-division multiplexing (WDM) optical communication networks. It allows for flexible and dynamic routing of...

RGB stands for red, green, blue, which are the primary colors of light used in additive color mixing. The RGB color model is widely used in various electronic displays, such as computer monitors,...

The discernment of depth or apparent difference in distance that causes the object to stand out from its background because of stereoscopic vision. The impression of relief can be obtained from the...

The light-sensitive cells on the retina of the eye that are responsible for low-resolution, peripheral vision.

Developed for use in military reconnaissance systems, it consists of a polygonal mirror, drive motor, interface between motor and mirror, and control electronics. Also used in broadband video...

A direct-readout television pickup tube.