Photonics Dictionary

3D printing, also known as additive manufacturing (AM), is a manufacturing process that builds three-dimensional objects layer by layer from a digital model. This technology allows the creation of...

3D profiling, also known as three-dimensional profiling, refers to the process of capturing, analyzing, and visualizing the three-dimensional shape, geometry, and surface characteristics of objects...

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 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 dispersion relation defined in order to value the reciprocal amount of dispersion. It is defined as the refractivity over the difference in index values of the shortest and longest visible...

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 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...

The absolute luminance threshold is the lowest luminance level of a light source or illuminated object that can be detected by the human eye under specific conditions. This threshold represents the...

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...

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...

The natural log of the ratio of absorbed intensity over the total intensity which gives a constant value assuming a stable volume as well as energy. In optical physics the absorbance may be defined...

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...

Absorptance refers to the fraction of incident electromagnetic radiation (such as light or infrared radiation) that is absorbed by a surface, rather than being reflected or transmitted. It is a...

An absorption band is a range of wavelengths, frequencies, or energies in the electromagnetic spectrum within which a substance absorbs radiation. It appears as a dark band in a spectrum where the...

The absorption index represents the imaginary component of the complex index of refraction, and not the real component. The imaginary component may characterize the attenuation per unit length...

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...

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...

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...

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...

An absorption spectrum is a graphical representation of the absorption of light by a material as a function of wavelength, frequency, or energy. It displays the specific wavelengths of light that are...

The measured change in absorption at a single wavelength while altering experimental parameters such as the incident intensity or pulse width.

In various scientific fields, the term acceptor has distinct meanings: Chemistry: An acceptor is an atom, ion, or molecule that receives electrons during a chemical reaction. In the context of...

An achromat, in the context of optics, refers to a type of lens or lens system designed to reduce chromatic aberration. Chromatic aberration is an optical phenomenon where different colors of 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...

In color perception and vision an achromatic point refers to a color stimulus that appears neutral or without hue, often perceived as a shade of gray. It represents a point in color space where the...

Achromatism refers to the optical property of a lens, prism, or optical system that minimizes or eliminates chromatic aberration. Chromatic aberration is the phenomenon where different wavelengths...

An acoustic surface wave, often abbreviated as ASW, is a type of mechanical wave that travels along the surface of a material, such as a solid or a liquid, rather than propagating through its volume....

Acousto-optic deflection refers to a phenomenon where the trajectory of light is altered by acoustic waves propagating through a material. This effect is utilized in acousto-optic devices, which are...

Acousto-optic diffraction refers to the process where light passing through an optically transparent material is diffracted due to the modulation of its refractive index by an acoustic wave...

Acousto-optic modulation refers to the process of using acoustic waves to modulate the properties of light passing through an optically transparent material. This modulation occurs due to the...

An acousto-optic modulator (AOM) is a device that utilizes the acousto-optic effect to modulate the amplitude, phase, frequency, or polarization of a laser beam or other coherent light source. It...

An acousto-optic tunable filter (AOTF) is a device that utilizes the acousto-optic effect to selectively filter and transmit light based on its wavelength or frequency. It operates by applying an...

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...

Acrylic refers to a type of synthetic polymer material known for its versatility, clarity, and durability. It is commonly used in a wide range of applications due to its beneficial properties. Here...

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...

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...

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...

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 active matrix organic light-emitting diode (AMOLED) display is a type of flat-panel display technology that combines the active matrix addressing scheme with organic light-emitting diodes (OLEDs)....

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...

Visual acuity specifically refers to the clarity or sharpness of vision, typically measured by the ability to discern the details of objects at a specific distance. It is a fundamental measure of the...

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...