Photonics Dictionary

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...

A hologram in which diffraction is produced by the silver image, resulting in a dimmer image than in a phase hologram, where diffraction takes place at the gelatin relief image left once the silver...

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,...

Area scan, in the context of imaging and cameras, refers to a method of capturing an entire two-dimensional image in a single snapshot or exposure. Unlike line scan, which captures images one line at...

An atomic absorption spectrometer (AAS) is an analytical instrument used to determine the concentration of specific chemical elements in a sample by measuring the absorption of light at...

An atomic clock is a highly precise timekeeping device that uses the vibrations or oscillations of atoms as a reference for measuring time. The most common type of atomic clock uses the vibrations of...

An atomic force microscope (AFM) is a high-resolution imaging and measurement instrument used in nanotechnology, materials science, and biology. It is a type of scanning probe microscope that...

Attenuated total reflectance (ATR) spectroscopy is a technique used in analytical chemistry to obtain IR spectra of samples. It is particularly useful for analyzing solid and liquid samples without...

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...

Autofluorescence refers to the natural emission of fluorescence exhibited by certain biological structures or molecules when exposed to light. Unlike fluorescence that results from the application of...

Backscatter refers to the phenomenon in which radiation or waves are scattered backward, opposite to the direction of the incident beam. This occurs when the incident radiation encounters a target or...

Bioluminescence is a natural phenomenon in which living organisms produce and emit light through a chemical reaction occurring within their bodies. This light emission is typically the result of a...

A biomarker, short for biological marker, refers to a measurable and quantifiable indicator of a biological condition, process, or response. Biomarkers can be substances or characteristics that are...

Biometrics refers to the automated recognition of individuals based on their physiological or behavioral characteristics. These unique attributes are used to verify or identify individuals, often in...

The action of a biological system responding to a single or multiple coherent particles of light produced from a laser source. Examples of laser biostimulation include: retinal interaction of light...

Birefringence is an optical property of certain materials that causes them to exhibit different refractive indices for light of different polarizations. In other words, when light passes through a...

Brightfield refers to a type of microscopy and imaging technique in which the specimen is illuminated with a white light source, and the image is observed or captured against a bright background. In...

Brillouin scattering is a phenomenon in physics where an incident electromagnetic wave (usually light) interacts with acoustic phonons (quantized lattice vibrations) in a material, resulting in the...

A calcium indicator is a molecule that is sensitive to changes in calcium ion (Ca2+) concentrations in biological systems. These indicators are commonly used in various fields, including cell...

An analog signal capable of being modulated as to frequency, amplitude or phase to carry information.

A CCD camera, or charge-coupled device camera, is a type of digital camera that utilizes a CCD image sensor to capture and record images. CCD cameras are widely used in various applications,...

A CCD image sensor, or charge-coupled device image sensor, is a type of electronic device used to convert optical images into electronic signals. It is a key component in digital cameras, camcorders,...

A charge-coupled device (CCD) is a type of electronic image sensor used in various imaging devices, including digital cameras, camcorders, and scientific instruments. It consists of an integrated...

A charge-injection device (CID) refers to a class of devices that manipulate and detect electrical charge within a semiconductor material. Charge-coupled devices are a specific implementation of this...

Chirality is a property of certain molecules and objects in which they are non-superimposable on their mirror images. In other words, a chiral object or molecule cannot be exactly superimposed onto...

Chirped pulse amplification (CPA) is a technique used in laser physics to amplify ultrashort laser pulses to high energies without causing damage to the amplifying medium. The method was first...

CID, or charge injection device, camera refers to a type of imaging device that utilizes a specific kind of solid-state image sensor technology. CID cameras are capable of capturing images in a...

A type of spectroscopy used extensively in the analysis of biological samples. Because most biologically synthesized molecules, such as proteins, are optically active, circular dichroism spectroscopy...

Circular dichroism (CD) is a spectroscopic technique used to study the structural characteristics of chiral (asymmetric) molecules, particularly biomolecules like proteins, nucleic acids, and certain...

A CMOS camera refers to an imaging device that employs a complementary metal-oxide-semiconductor (CMOS) image sensor to capture digital images. CMOS cameras have become ubiquitous due to their low...

A CMOS image sensor, short for complementary metal-oxide-semiconductor image sensor, is a type of semiconductor device used to capture visual information and convert it into electrical signals for...

A coherent fiber bundle (CFB), also known as a coherent fiber optic bundle, is an assembly of multiple optical fibers arranged in a specific geometric pattern to maintain the spatial coherence of...

Cold atoms refer to atoms that have been cooled to extremely low temperatures, typically in the microkelvin (µK) to nanokelvin (nK) range, close to absolute zero (0 Kelvin or -273.15°C). At...

A color center, in the context of materials science and condensed matter physics, refers to a specific type of crystallographic defect in a crystalline structure that introduces color to the...

A technique used to store wavefront information on thin polarization information-recordable materials by controlling the polarization angle of a small illuminating spotlight in each sampling cell on...

A computer-generated hologram (CGH) is a holographic image produced using computational methods and algorithms, rather than traditional optical techniques. CGHs are generated entirely in digital form...

Continuous wave (CW) refers to a type of signal or transmission where the signal is constant and does not vary with time. In various contexts, the term is used to describe continuous, uninterrupted...

A cryostat is a device used to maintain very low temperatures, typically below the boiling point of liquid nitrogen (77 K or -196°C) or even lower. It provides a controlled environment for...

Deep multiphoton microscopy is an advanced imaging technique used in biological and biomedical research to visualize structures and processes deep within tissues with high resolution. It combines the...

Deep ultraviolet (DUV or deep-UV) refers to a specific range of ultraviolet light with shorter wavelengths than those in the UV-A and UV-B regions. The exact wavelength range considered as DUV can...

Dense wavelength division multiplexing (DWDM) is an optical communication technique used to increase the data-carrying capacity of optical fiber networks by simultaneously transmitting multiple...

Dichalcogenides are a class of compounds composed of two atoms of a chalcogen element bonded to a single atom of a metal or metalloid element. Chalcogens are the elements in group 16 of the periodic...

Dichroism refers to the property of certain materials to exhibit different colors or absorbance of light depending on the direction of light propagation or polarization. The term is commonly used in...

Differential interference contrast (DIC) microscopy, also known as Nomarski interference contrast microscopy, is an optical imaging technique used in microscopy to enhance the contrast of transparent...

The logarithm of the reciprocal of diffuse transmittance. Diffuse density results when a sample is diffusely illuminated.

Digital holographic microscopy (DHM) is an advanced imaging technique that combines holography and digital image processing to capture and reconstruct three-dimensional images of objects. This method...