Photonics Dictionary: A

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...

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...

The term acute bisectrix is used in mineralogy and crystallography to describe a specific optical property of minerals, particularly in relation to their crystal structure and light behavior. ...

An optical adapter typically refers to a device or component used in optical systems to facilitate connections between different types of optical fibers, connectors, or interfaces. Here are a few...

Optical addressability refers to the capability to control or manipulate individual elements that emit or modulate light (such as pixels in a display or light sources in an optical network) using...

Optical thin film adhesion specifically refers to the adhesion properties of thin films used in optical applications. Here’s a detailed definition: Thin film materials: Optical thin films...

An intermolecular substance that serves to hold materials together. Two types are used in the optical industry: one, which must be transparent and colorless, to cement lenses together; and a...

Adiabatic laser colorimetry is a technique used to measure the color of materials based on the principle of adiabatic demagnetization. Principle: Adiabatic laser colorimetry relies on the...

An optical illusion in which distant objects are lighter in tone and less distinct in outline than those closer to the observer because of the atmospheric diffusion of light.

The use of optical or electronic recording systems to extract information from the terrain, while aloft, for reconnaissance applications.

An optical system with object and image points at infinity. Literally, "without a focal length."

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 support device in which a column or chamber of air permits the free travel of a mobile part. In optical mounting and positioning equipment, air bearings are of two types, linear or rotary,...

The central peak (including everything interior to the first zero or dark ring) of the focal diffraction pattern of a uniformly irradiated, aberration-free circular optical element or system.

An optical tooling instrument consisting of an objective lens, a focusing lens, an optical micrometer, a reticle and an eyepiece. The alignment telescope projects a precise line of sight to which a...

Left- and right-hand circularly polarized beams that are produced at different velocities by passing plane-polarized light through an optical substance. When recombined, they exhibit different phases...

The disordered, glassy solid state of a substance, as distinguished from the highly ordered crystalline solid state. Amorphous and crystalline phases of the same substance differ widely in optical...

Broadband radiation emitted by a laser that does not transmit through the optical element. It can be removed by filtering.

A device that enlarges and strengthens a signal's output without significantly distorting its original waveshape. There are amplifiers for acoustical, optical and electronic signals.

A type of fiber optic sensor that detects alteration in position, distance, pressure, liquid level or temperature by transmitting light across a gap to a reflector; a change in the light returned to...

An optical device, such as a Nicol prism, capable of producing plane-polarized light, and used for detecting the effect of the object on plane-polarized light produced by the polarizer.

An optical system with different focal lengths or magnification levels in perpendicular planes to the optical axis.

A state in which an image is distorted by an optical system.

A lens that distorts an optical image.

An angle formed by the lines of sight of both eyes when focusing on an object. Also, the rate at which a ray approaches the optical axis.

Angular deviation from the optimum alignment of source to optical waveguide, waveguide to waveguide, or waveguide to detector, resulting in a loss of optical power.

The angular spectrum approach is a mathematical and computational technique used in the field of optics to analyze and simulate the propagation of optical waves, particularly in the context of wave...

The measured planar or solid angle of related aspects of an optical system with respect to an optical axis.

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,...

The process of heating and slowly cooling a solid material, like glass or metal, to stabilize its thermal, electrical or optical properties or, as in semiconductor materials, to reverse lattice...

An oven or furnace that possesses the design requirements and heat control necessary to anneal glass for the optical industry.

An optical instrument that uses a yellow light of varying intensity with red and blue lights of fixed intensity to test for colorblindness.

A coating that is capable of stopping the condensation of moisture on an optical surface.

An antireflection coating (AR coating) is a thin film or coating applied to optical surfaces, such as lenses or windows, to minimize unwanted reflections and increase the transmission of light...

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...

The second adjustable iris diaphragm in an optical system. In the common microscope condenser system, it usually is located beneath the substage condenser on a transmitted light microscope. When the...

Aplanatic points refer to specific points in an optical system where certain aberrations, such as spherical aberration or coma, are minimized or eliminated. In an optical system, aberrations are...

An aplanatic surface is an optical surface that is specifically designed or shaped to minimize spherical aberration and coma. Spherical aberration is an optical aberration that occurs when light rays...

An apochromat, often referred to as an apochromatic lens or apochromatic objective, is a type of optical system designed to minimize chromatic aberration. Chromatic aberration occurs when different...

An optical system that is corrected chromatically for three colors simultaneously.