Photonics Dictionary

A specific type of filter designed to reduce the amount of light scattered by reflections from the edges of optical components or mounts, or from irregularities on the optical surfaces.

Accessible emission typically refers to the portion of emitted radiation (light, particles, etc.) from a source that can be effectively detected, measured, or utilized by an observer or device. This...

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...

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...

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 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...

A condenser that forms a hollow cone-shaped beam of light with its focal point in the plane of the specimen. If it is used with an objective having a numerical aperture lower than the minimum...

A technique whereby the sample is illuminated by a hollow cone of light larger than the acceptance angle of the objective, so that only scattered light is seen, revealing any irregularities of the...

A lidar (light detection and ranging) technique used in pollution monitoring. Two light beams are emitted simultaneously, one at a wavelength that will be absorbed by the target particles, and the...

Diffuse reflectance spectroscopy (DRS) is a nondestructive analytical technique used to investigate the optical properties of materials, particularly in the field of spectroscopy. Unlike traditional...

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...

A single-particle scattering technique in which an incident laser beam is tightly focused by means of lenses to yield a focal spot in the scattering material with a diameter on the order of the...

An interference pattern that is recorded on a high-resolution plate, the two interfering beams formed by a coherent beam from a laser and light scattered by an object. If after processing, the plate...

A holographic camera, also known as a holographic imaging system or holographic recorder, is a specialized device used to capture 3D holographic images of objects or scenes. Unlike conventional...

Holographic tomography is an advanced imaging technique that combines holography and tomography to provide three-dimensional reconstructions of transparent or weakly scattering objects with high...

Holography is a technique used to capture and reconstruct three-dimensional images using the principles of interference and diffraction of light. Unlike conventional photography, which records only...

Device which determines particle velocity through the measurement of scattered interference of a beam pair from a single source. The measured light is Doppler shifted which provides information...

A scattering photometer using scattered light in the solid angle 4.51+0 19° with respect to the forward direction, and an impactor with a rectangular jet. Scattered light intensities of entering...

Light diffusion refers to the process by which light is scattered or spread out in various directions as it interacts with a medium or material. Unlike direct transmission through a transparent...

A long-pass filter is an optical filter that allows longer wavelengths of light to pass through while blocking or attenuating shorter wavelengths. These filters are designed to transmit light with a...

Mie scattering, named after the German physicist Gustav Mie, refers to the scattering of electromagnetic radiation (such as light) by spherical particles. Unlike Rayleigh scattering, which is...

Zone of laser operation in which the direct, reflected or scattered light exceeds the laser's MPE and (by ANSI standards) requires the use of protective eyewear.

Optical coherence tomography (OCT) is a non-invasive imaging technique used in medical and scientific fields to capture high-resolution, cross-sectional images of biological tissues. It provides...

Also known as an optical diode, an optical isolator is a device that utilizes the Faraday effect to suppress or redirect backscattered or backreflected light in order to allow light transmission in...

Optical strain sensors are devices that utilize optical principles to measure the deformation or strain experienced by a material under mechanical stress. These sensors convert changes in strain into...

An optical testing instrument is a device or system used to evaluate and measure the performance, quality, and characteristics of optical components, systems, and devices. These instruments play a...

An optical time-domain reflectometer (OTDR) is a specialized instrument used in optical fiber communications to characterize and analyze the optical fibers' characteristics, including attenuation,...

A method for characterizing a fiber wherein an optical pulse is transmitted through the fiber, and the resulting light scattered and reflected to the input is measured (by an optical time-domain...

Present in photocurrent burst, it is the low frequency pulse that corresponds to the light scattered from the beams in the absence of heterodyne mixing.

Spectroscopy used to study the concentration, diffusion and Brownian motion of small particles suspended in a fluid by measuring dynamic fluctuations of light that is scattered or fluoresced by the...

Raman scattering, also known as the Raman effect or Raman spectroscopy, is a phenomenon in which light undergoes inelastic scattering when interacting with matter, such as molecules, crystals, or...

Raman spectroscopy is a technique used in analytical chemistry and physics to study vibrational, rotational, and other low-frequency modes in a system. Named after the Indian physicist Sir C.V. Raman...

Rayleigh scattering is a phenomenon that occurs when light waves interact with particles or molecules that are much smaller than the wavelength of the light. It is named after the British scientist...

A scanning electron microscope (SEM) is a powerful imaging instrument used in scientific research, materials characterization, and various industrial applications. Unlike traditional optical...

Scanning electron microscopy (SEM) is an advanced imaging technique used in microscopy to obtain high-resolution, three-dimensional images of the surfaces of solid specimens. SEM achieves this by...

Measure of the interference fringe pattern produced by the forward scattering of light by an optical fiber; the fringe pattern is inversely proportional to the fiber diameter.

The portion of light scattered when traveling through a unit thickness of material.

A measurement technique used for the rapid quantitative evaluation of surface quality based on the detection and analysis of light scattered from the surface.

Sisyphus cooling is a technique used in atomic physics to achieve ultracold temperatures of atoms or molecules by exploiting the periodic motion of particles in optical traps or lattices. The name...

Spectral domain optical coherence tomography is an imaging technique used in medical diagnostics, particularly in ophthalmology, to visualize and analyze the internal structures of biological...

In Stimulated Brillouin Scattering (SBS), an incident photon (usually laser light) interacts with acoustic phonons in a medium. The energy and momentum of the incident photon are transferred to the...

Light from a pulsed laser focused into nonsaturable absorbing fluid that generates a strongly backscattered light beam with a frequency higher than that of the incident light.