Photonics Dictionary

In optics, the Pockels effect refers to the phenomenon where the refractive index of a material changes in response to an applied electric field. This effect is utilized in Pockels cells, which are...

1. With respect to angular subtense, a source of light, such as a star, that is very small. In a lab, a point source may be simulated by imaging a large source onto and through a pinhole, or by...

A crystal-based device that combines and adjusts the intensities of multiple wavelengths of laser light in order to obtain the desired output wavelength.

A polygonal mirror, also known as a multifaceted mirror or facet mirror, is a type of optical component used in various laser systems, optical scanners, and imaging devices. It consists of a flat or...

An instrument that measures the angle at which a prism can couple laser light into an optical waveguide; used to determine the thickness and refractive index of thin films in integrated optical...

Q-switched operation, or q-switching, is a technique used in lasers to produce short and intense pulses of light. The term "Q" in q-switching stands for "quality factor," which is a measure of the...

Q-switching, short for "quenching-switching," is a technique used in lasers to generate short, high-energy pulses of light. The term "Q" refers to the quality factor of the laser cavity, which...

A quantum cascade laser (QCL) is a type of semiconductor laser that operates based on the principles of quantum mechanics. It is a versatile and powerful device used for emitting coherent light in...

A quantum well is a structure in quantum mechanics that confines particles, such as electrons or holes, in one spatial dimension. This confinement leads to quantized energy levels, creating a...

A flexible fiber cable with a small diameter that transports light from the excitation laser to the target. Used in Raman spectroscopy, the probe is capable of obtaining high-quality data at high...

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...

Rare earth dopants refer to elements from the lanthanide series, also known as rare earth elements, that are intentionally introduced into the crystal lattice of a material to modify its properties....

An image that appears when a hologram is illuminated by a suitable light source, generally a laser beam.

A device employed to identify toxic agents lingering on the ground or in the air from up to three miles away, by using laser beams to detect infrared light-absorption patterns that can be analyzed to...

A resonator is a device or system that exhibits resonance, which is a phenomenon that occurs when an external force or stimulus is applied at a specific frequency, causing the system to oscillate...

Retroreflection is a phenomenon in optics where light is reflected back toward its source, typically in a direction nearly parallel to the direction from which it originated. This occurs due to the...

A retroreflector is an optical device or structure that reflects incident light or electromagnetic waves back to their source, regardless of the direction from which the light approaches. Unlike...

Rhodamine refers to a family of fluorescent organic dyes that are widely used in various fields, including biology, chemistry, medicine, and materials science. These dyes are known for their bright...

A ring laser gyroscope (RLG) is a type of gyroscope that uses laser light to detect and measure changes in orientation. It operates based on the Sagnac effect, which is a fundamental principle of...

A Risley prism, also known as a Risley prism pair or Risley rotating prism, is an optical device used for controlling the direction of a laser beam or other optical beam by independently rotating two...

A structured light device using a rapidly rotating laser to project a beam of light that appears to the human eye as a continuous circle; used as a reference marker on walls or landscape for...

A Rugate filter is a type of optical filter that is designed to have a continuously varying refractive index profile throughout its thickness, rather than the discrete layers found in traditional...

Sapphire optical fiber is a type of optical fiber made from single-crystal sapphire, which is a form of aluminum oxide (Al2O3) that is highly transparent in the infrared region of the electromagnetic...

A sapphire window refers to a transparent optical component made from sapphire crystal. Sapphire is a single-crystal form of aluminum oxide (Al2O3) that is highly prized for its exceptional optical...

A saturable absorber is a type of optical device that exhibits variable absorption properties depending on the intensity of incident light. In essence, it becomes less absorbent as the light...

1. The variation in intensity of a light beam as it travels through the atmosphere. 2. In radiation physics, a light flash formed by an ionizing event in a phosphor; a flash formed when rapidly...

A nonlinear label-free imaging technique commonly used during surgical procedures for the visualization of collagen fibers and muscle tissue (myosin) with submillimeter resolution. During the...

Second-order nonlinear optical properties refer to a class of phenomena exhibited by certain materials in response to intense light, typically in the realm of optics and photonics. Nonlinear optical...

Selective laser melting (SLM) is an additive manufacturing (AM) or 3D printing technology that belongs to the powder bed fusion category. SLM is primarily used for metal additive manufacturing, where...

Self-phase modulation (SPM) is a nonlinear optical phenomenon that occurs when an intense laser beam passes through a medium, causing a change in the phase of the light due to its interaction with...

A single-photon avalanche diode (SPAD) is a specialized type of photodetector designed to detect extremely weak optical signals, down to the level of single photons. SPADs are widely used in...

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...

A solid-state laser is a type of laser that uses a solid gain medium (as opposed to a liquid or gas) to produce coherent light. The term "solid-state" refers to the fact that the active medium, where...

Any isolated wave that propagates without dispersion of energy. Specifically to photonics, an ultrashort pulse of laser light that propagates through a waveguide without characteristic chromatic...

A spatial light modulator (SLM) is an optical device that modulates or manipulates the amplitude, phase, or polarization of light in two dimensions, typically in the form of an array. SLMs are...

Spatially offset Raman spectroscopy (SORS) is a technique that extends traditional Raman spectroscopy by incorporating measurements at different spatial offsets. This method allows for the selective...

Refers to the variety of techniques that use the interference pattern produced by laser light diffusely reflected by an object. There are two basic techniques: direct laser photography, used when...

Spectral flow cytometry is an advanced flow cytometry technique that expands the capabilities of traditional flow cytometry by utilizing spectral information from fluorochromes to enhance...

A spheric lens, also known as a spherical lens, is a type of optical lens with at least one surface that is part of a sphere. This means that the lens surface is curved in a symmetrical manner,...

STED microscopy, or stimulated emission depletion microscopy, is a superresolution imaging technique in fluorescence microscopy that surpasses the diffraction limit, enabling the visualization of...

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.

A streak camera is a specialized instrument used to capture and analyze ultrafast phenomena, such as extremely short pulses of light or rapidly changing events. Unlike traditional cameras that...