Photonics Dictionary

An instrument devised by Nichols and Hull for use in the measurement of radiation pressure. The device has two small silvered, glass mirrors that are suspended, in the way of a torsion balance, by a...

A prism invented by William Nicol in 1828 that is made of calcite, the end faces of which are ground to an angle of 68° between one vertical side and the end surface. The prism is cut diagonally...

A device that uses low-level visible radiation or infrared radiation to produce a visual image of a night scene. These devices may rely on the amplification of existing visible light by...

A device consisting of a disc with a spiral arrangement of holes that is used to convert visible patterns into electrical patterns. Light is reflected from the subject and focused through a vertical...

Unit of measurement of brightness (luminance) equal to one candela per square meter.

A pollution-measuring device used to detect the presence of nitric oxide regardless of other gases present. It utilizes the principle of laser magnetic resonance (LMR).

A nitrogen vacancy (NV) refers to a specific type of defect or impurity in a crystal lattice where a nitrogen atom replaces a carbon atom adjacent to a vacancy (an empty lattice site) in the diamond...

The value of the distance of distinct vision, minimum focusing distance or near point, divided by the focal length of the lens. Magnification is produced when the optic is placed at its focal...

Stimulating light used for the production of energy through photosynthesis, solar cell or other light senstitive device.

That point in the electromagnetic spectrum at which an optical system focuses the most chemically effective rays.

Glass designed to absorb most infrared and ultraviolet radiation while transmitting most of the visible region.

Electromagnetic energy that is capable of producing photochemical activity.

Any of a series of radioactive elements with atomic numbers ranging from 89 to 103.

The creation of a chemical reaction in a substance when radiation is directed to it.

A cathode-ray tube having a screen that is coated on the back with a thin film of aluminum, which serves to intensify the propagation of light.

The process of applying a film of aluminum to a surface, usually by evaporation in a vacuum.

Charged frozen pellets that are rapidly bombarded with a focused high-power laser to form a dense plasma that can be heated and sustained with neutral beams.

A visual defect that produces a disparity in the sizes of the images formed by the two eyes.

A light source that emits an uneven distribution of radiant energy through the visible range.

Anisotropic is a term used to describe a material or substance that exhibits different properties or behaviors in different directions. In other words, the physical or mechanical characteristics of...

Anisotropy refers to the property of exhibiting different values or characteristics when measured in different directions. In various fields, including physics, materials science, and geology,...

Gamma ray radiation released when matter and antimatter, such as electron and positron, unite and eliminate each other, transforming completely into energy. The resulting gamma ray spectrum depends...

The plot that expresses a reaction rate vs. the reciprocal of absolute temperature. Often used to describe the thermal characteristics of laser applications such as ablation or annealing.

A dark red opaque material that is transparent to the infrared beyond 1 µm.

The unit generally used to express distances within the solar system, and sometimes to measure interstellar distances. Technically, one astronomical unit is the mean distance between the Earth and...

Attosecond photonics sources refer to devices or systems that generate extremely short pulses of light on the order of attoseconds (1 attosecond = 10-18 seconds). These ultrafast light pulses are in...

A type of fiber optic connector consisting of two cone-shaped ferrules aligned by a mating sleeve.

Combining adjacent pixels into one larger pixel, resulting in increased sensitivity and lower resolution, or, in image analysis, excluding objects based on shape, position or area.

A device having a pair of decentered lenses, one for each eye, that focuses on a single object as a magnifier. It is often supplied with a forehead fixture or an elastic headband to leave the hands...

The application of observed operational processes of sophisticated living organisms to mechanical and electrical systems in order to analogize capabilities or efficiency.

The technology that deals with the interaction of organic materials with light and other forms of radiant energy whose quantum unit is the photon. This includes the emission, detection, absorption,...

Crystal growth method that resembles static freeze, but that induces growth by removing the ampoule from the furnace so that the freezing-point temperature gradient is unchanged during the growth...

The behavior of microscopic solid particles suspended in a fluid, first observed by botanist Robert Brown in 1827 as a continuous random motion.

A convex lens that brings an incident bundle of rays to a focus to produce intense heat at the focus.

The process of lapping a thin edge of metal over the bevelled edge of a lens to maintain it within its cell.

Carbonization is a process in which organic materials are heated in the absence of air, leading to the decomposition of the material and the production of carbon-rich residue. During carbonization,...

A surface heat-treating process that produces a highly stressed surface. In case-hardening of glass, a plate of glass is heated almost to the softening point and then cooled quickly in a blast of...

The computer module whose circuitry interprets instructions and guides the actions of the peripherals. Also known as the mainframe.

A photocathode that exhibits maximum sensitivity in the blue and ultraviolet regions of the spectrum. The sensitivity is obtained by the exposure of a thin layer of antimony to cesium vapor at an...

Chalcogenide refers to a class of compounds containing elements from group 16 of the periodic table, which includes sulfur (S), selenium (Se), and tellurium (Te). These elements are known as...

Proprietary name for a low-light-level TV pickup tube.

A technique for polishing silicon in which an alkaline suspension containing silicon dioxide particles creates a soft layer of silicon hydroxide, which is then removed, leaving a surface with the...

Scanning characterized by the generation of a plane or right circular cone with a vertex angle of about 180° by the direction of maximum radiation.

The halo phenomenon of a brightly colored arc having the colors of the rainbow and lying parallel to the horizon.

In optics, degreasers or ultrasonic arrangements used for removing pitch, cement or polishing material from lenses during manufacture. It also may refer to manual cleaning devices used immediately...

The application of photography, with the exception of radiography, to obtain pictures of parts or the whole of a patient to make a diagnosis.