Photonics Dictionary: A

Ablative photodecomposition refers to a process where a material is broken down or decomposed due to exposure to intense light, typically laser light. In this process, the photons from the laser...

An abridged spectrophotometer refers to a simplified or compact version of a traditional spectrophotometer, which is a scientific instrument used to measure the intensity of light at different...

Measures the absorption or sample transmittance over a range of specified wavelengths. Sample may be placed within the device and the transmission measured to an accuracy of given percent. The...

The acousto-photorefractive effect refers to a phenomenon in which acoustic waves (sound waves) interact with light waves (photons) within a photorefractive material, resulting in changes in the...

An accelerator at the Argonne National Laboratory, providing powerful x-ray beams for materials research applications.

The application of aerial photographs as a means of measurement in map making and surveying.

Photographing of terrain on the ground and objects in the air by cameras mounted in aircraft; utilized in satellites, multispectral scanning and intricate data handling systems.

Agri-photonics refers to the application of photonics technologies in agriculture. Photonics involves the generation, manipulation, and detection of light and other forms of radiant energy whose...

A category of systems designed to communicate a photo taken from the air (e.g., aircraft, balloon, satellite) to a ground station. It can be done by direct television transmission of the photo, or by...

A photocell having an alloy junction formed by combining an indium disc with a thin wafer of N-type germanium.

The use of mathematical analysis to derive solutions in the science of photogrammetry.

The use of photographs -- motion picture or still -- to establish if a particular event exists.

The use of photographs taken from specially placed cameras, to develop, through computation, a spatial solution of the photographed phenomenon.

A spectral phenomenon in which the degree of the photoresponse of an illuminated semiconductor is determined by the wavelength composition of the incident light.

The use of photographs to record astronomical objects and phenomena for purposes of physical observation and measurement of motion, radiation and spectra.

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 device that utilizes avalanche multiplication of photocurrent by means of hole-electrons created by absorbed photons. When the device's reverse-bias voltage nears breakdown level, the hole-electron...

An APD detector, or avalanche photodiode detector, is a type of photodetector used to detect light or optical signals by converting incoming photons into electrical current. It operates based on the...

An Abbe condenser is a type of optical component used in microscopy to enhance the illumination of the specimen. Named after the German physicist Ernst Abbe, who developed it in the 19th century, the...

A form of roof prism used to invert an image. The prism has faces cut normal to the optical axis; therefore, the prism may be placed within the optical path of a system and invert the image without...

An Abbe refractometer is a scientific instrument used to measure the refractive index of liquids and solids. Named after the German physicist Ernst Abbe, this device operates on the principle of...

Absolute white is a term used in color science and imaging to describe a reference white point that represents the brightest, most neutral white achievable. It serves as a standard for measuring and...

An absorbing wedge is an optical device used to control the intensity of light passing through it by absorbing a portion of the light. It is typically used in experiments and optical systems where...

An absorption hologram is a type of hologram in which the image is formed by variations in the absorption of light within the recording medium. Unlike traditional holograms that rely primarily on...

An absorption line is a dark line in a spectrum that occurs when a specific wavelength of light is absorbed by atoms or molecules in a medium (such as a gas or a solid) as light passes through it....

An absorption peak refers to a sharp increase or spike in the absorption of electromagnetic radiation at a particular wavelength or energy level. It is a distinctive feature in the absorption...

Absorption spectroscopy is a fundamental analytical technique used to study the interaction between electromagnetic radiation and matter. It involves measuring the absorption of light by a sample...

The range of angle or solid angle values by which light may enter an optical system.

The acceptance pattern, often used in the context of antennas and optical systems, refers to the spatial distribution of the sensitivity or responsiveness of a device to incoming signals or light....

An achromatic lens is a type of optical lens designed to minimize chromatic aberration, which is the inability of a lens to focus all colors of light to the same convergence point. Chromatic...

An achromatic prism is a type of prism designed to separate white light into its component colors (spectrum) without causing chromatic aberration. Unlike regular prisms, which disperse light but also...

Acoustical holography is a technique used to visualize and analyze sound fields in three-dimensional space. It involves capturing the complex spatial distribution of acoustic waves, much like how...

An acousto-optic modulator (AOM) is a device that utilizes the interaction between sound waves and light waves to modulate or control the intensity, frequency, phase, or direction of laser beams. It...

Acousto-optic refers to the interaction between sound waves and light waves within a material medium, where acoustic waves (sound waves) influence the optical properties of the material. This...

Acousto-optics is a branch of physics that deals with the interaction of sound waves (acoustic waves) and light waves (optical waves) within a medium. It primarily focuses on phenomena where acoustic...

Actinic refers to the property of radiation, particularly ultraviolet (UV) light, that can cause photochemical reactions. Radiation: Actinic radiation typically involves UV light but can also...

Actinic focus refers to the point or plane within an optical system where ultraviolet (UV) light or other actinic radiation converges to form the sharpest possible image. Here are the key aspects: ...

Actinic glass is a type of glass specifically designed to filter or block ultraviolet (UV) light and other forms of actinic radiation. UV filtering: Actinic glass effectively absorbs or...

Actinic radiation refers to electromagnetic radiation that has enough energy to induce photochemical reactions. This type of radiation is primarily in the ultraviolet (UV) range but can also include...

Actinism refers to the property of radiation, particularly light, that enables it to produce photochemical effects. This term is derived from the Greek word aktinos, meaning ray. Here are the key...

Actinochemistry refers to the branch of chemistry that studies the chemical effects of radiation, particularly light, on substances and chemical reactions. Here are the key aspects of...

An actinometer is a device used to measure the intensity of radiation, particularly solar radiation or light, often with a focus on its ability to cause photochemical reactions. Here are the key...

Actinometry refers to the measurement of the intensity of radiation, particularly light, with a specific focus on its ability to cause photochemical reactions. It involves quantifying the amount of...

An active infrared (IR) system is a type of technology that uses infrared radiation actively emitted and detected by sensors for various purposes. Here are the key features and applications of active...

In the context of semiconductors and electronics, the active layer is the part of a semiconductor device where the essential electronic activities take place. This includes the movement and...

An active medium is a material or substance used in various optical devices and systems, where it plays a critical role in amplifying light or producing laser beams through the process of stimulated...

In the context of a laser diode, the active region is a critical part of the device where the primary light generation occurs. Laser diode active region: The active region in a laser diode is...

Radioactivity refers to the spontaneous emission of radiation from the nucleus of an unstable atom. This emission occurs as the nucleus undergoes radioactive decay, which is a natural and random...

Acutance refers to the perceived sharpness of an image in terms of the contrast of edges, rather than the resolution of fine details. It relates to how well-defined and crisp edges appear in a...