Definitions

Abaxial spherical aberration, also called oblique spherical aberration, refers to a specific type of optical aberration that occurs in lens systems. It is a form of spherical aberration that affects...

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...

An Abbe-Porro prism, often referred to simply as a Porro prism, is an optical prism used in binoculars and other optical instruments to invert and reverse an image. It is named after the Italian...

An aberration sensor typically refers to a component or feature in optical systems, especially in telescopes or cameras, that detects and quantifies aberrations. Aberrations are imperfections or...

Optical surface damage due to abrasive rubbing. Abrasion damage affects are less than the thickness of the optical coating layers. Surface investigation may be achieved by aluminization of the coated...

Powder used to produce a smooth optical surface through abrasive polishing. Compounds may produce a surface finish specified for each.

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...

An absorption lens is a type of optical lens that not only focuses or diverges light but also significantly absorbs certain wavelengths of the incident light. This dual function makes it different...

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 acoustical hologram refers to a three-dimensional representation of sound waves in space, analogous to optical holography but applied to acoustic waves. Unlike visual holography, which creates...

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 deflector (AOD) is a type of device that utilizes the acousto-optic effect to control the direction of light beams. It operates by modulating the refractive index of an optically...

Active optics refers to a technology used in telescopes and other optical instruments to improve the quality of images by dynamically adjusting the shape of optical components, such as mirrors, in...

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...

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...

Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effects of atmospheric distortions. The Earth's atmosphere can cause light passing through it...

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...

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,...

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...

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 argon-fluoride (ArF) excimer laser is a type of ultraviolet laser that operates using a mixture of argon and fluorine gases. Excimer lasers are a class of gas lasers that emit light in the UV...

Not spherical; an optical element having one or more surfaces that are not spherical. The spherical surface of a lens may be slightly altered so as to reduce spherical aberration. Aspheric surfaces...

An optical system having one or more lens or mirror components that have nonspherical surfaces. These surfaces, whether reflecting or refracting, serve to advance or retard the incident wavefront,...

An aspheric lens is a type of lens whose surface profiles deviate from the traditional spherical shape. Unlike spherical lenses, which have a constant curvature across their surfaces, aspheric lenses...

An aspheric mirror is an optical mirror surface that deviates from the shape of a perfect sphere, having a non-spherical surface profile. Unlike traditional spherical mirrors, which have a curved...

The modification of the spherical surfaces in an optical system to correct for spherical aberration.

An astronomical mirror, also known as a telescope mirror or primary mirror, is a key component of a reflecting telescope. It serves as the primary optical element responsible for gathering and...

The area of optics in which the wave nature of a particle is exploited to carry out very accurate interferometry and other optical techniques with atoms instead of photons. In this process, particles...

An attenuator is an electronic or optical device used to reduce the power or intensity of a signal without significantly affecting its waveform or other characteristics. Attenuators are commonly used...

An autocollimator is an optical instrument used for measuring small angular deviations with high precision. It operates on the principle of autocollimation, where a light source is directed onto a...

An axicon is a type of optical component characterized by its conical shape and its ability to transform a collimated Gaussian beam of light into a ring-shaped beam with a gradually increasing...

Azimuthal polarization refers to a specific polarization state of light where the electric field vector of the electromagnetic wave points along the azimuthal direction (around the propagation axis)....

Azobenzene is a chemical compound consisting of two phenyl rings linked by a N=N double bond. It is well-known for its ability to undergo reversible photoisomerization, meaning it can switch between...

A ball lens is a small, spherical optical component typically made of glass or other transparent materials. It is characterized by its spherical shape, with both its front and back surfaces forming...

A beamsplitter is an optical device used to divide a beam of light into two or more separate beams, typically by reflecting a portion of the incident light while transmitting the remainder....

A defect on or in an optical element that does not appreciably impair the function of the surface.

1. That action occurring when light passes through an optical interface at other than normal incidence, i.e., refraction. 2. The curving of a path of light that passes close by a massive object, due...

Blaze height typically refers to a parameter in the context of diffraction gratings, which are optical devices consisting of a series of closely spaced parallel grooves or slits. The blaze height is...

A blur circle refers to the out-of-focus region in an image captured by an optical system. When an object in a scene is not in perfect focus, its image is spread out into a circular shape on the...

Brillouin microscopy is a non-invasive imaging technique that utilizes Brillouin scattering to measure the mechanical properties of materials at the microscale. This advanced optical technique...