Photonics Dictionary

A 3D profile sensor, also known as a 3D profiling sensor or 3D depth sensor, is a technology that is used to capture and measure the three-dimensional shape or profile of an object or a scene. These...

That layer in a semiconductor injection laser or light-emitting diode that provides optical gain.

The layer of material in a laser diode from which the optical radiation is emitted; light producing region

Diffuse light emitted by the atmosphere due to the excitation of particles of atmospheric gas. These excited particles release light that is visible from Earth as a faint luminescence in the night...

A host crystal for chromium that emits pulsed or continuous-wave laser light, tunable from about 720 to 790 nm.

An alexandrite laser is a solid-state laser that utilizes a synthetic crystal made from the rare earth element alexandrite (BeAl2O4:Cr3+). This crystal is capable of emitting laser light in the...

Any fluorescence in which the wavelength of the emitted light differs from that of the absorbed light.

A light source that emits an uneven distribution of radiant energy through the visible range.

An arc flash is a sudden release of electrical energy due to an electric arc — a continuous, high-current discharge of electricity between conductors or from a conductor to ground. Arc flashes...

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...

Spectrometric analysis of the distinct and characteristic spectra of atoms of elements. The atoms are energized to emit radiant energy, which, when dispersed by a prism or diffraction grating,...

The strongest light emitted by the Earth's upper atmosphere. It most often can be viewed in the Arctic as the aurora borealis, and in the Antarctic as the aurora australis.

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...

Azadioxatriangulenium is a type of organic compound with a unique triangular molecular structure. It is often abbreviated as ADOTA. This compound belongs to the class of polycyclic aromatic...

A device, either visual or electronic, that emits signals to identify set positions for use in the navigation of aircraft and ships along flight paths and channels, or as a warning against entering a...

A device used to compare the luminous intensities of two sources by locating a point between the two light sources where the produced flux densities are equal. The luminous intensities of the two...

A blue diode laser is a type of semiconductor laser that emits light in the blue wavelength range of the electromagnetic spectrum, typically between 400 and 500 nanometers. Diode lasers are compact,...

Broadband dielectric mirrors, also known as broadband mirrors, are optical coatings designed to efficiently reflect or transmit light over a broad range of wavelengths. These mirrors are constructed...

Cathode radiant sensitivity refers to the ability of a photocathode to convert incident radiant energy, typically in the form of light, into an electrical signal. Photocathodes are components used in...

Light produced when a metal is bombarded with high-velocity electrons causing small amounts of the metal to vaporize and emit radiation. Also known as electronoluminescence.

A lamp that emits light as the result of the passage of an electrical current through ionized cesium vapor.

Chip-on-board (COB) lights refer to a type of LED lighting technology where multiple LED chips are directly mounted onto a substrate, typically a printed circuit board (PCB), without the need for...

A layer between the corona and the photosphere of the sun; its emission is overwhelmed by light emitted by the underlying, denser photosphere.

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 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...

The two points on the principal axis of a mirror or lens so positioned that light emitted from either point will be focused at the other, i.e., object and image points.

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 type of photoelectric proximity mode sensing incorporating a lens system to focus the light from the emitter in a small, concentrated spot at a specific point in front of the sensor. Also referred...

An instrument designed to measure the proportion of light emitted by a source in the blue region of the spectrum.

A precision-engineered microminiature light source that is safe for darkroom use, yet emits a beam of light bright enough to read by.

An incandescent or fluorescent lamp whose emittance spectrum resembles that of daylight.

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...

The interval between direction of signal to a light-emitting diode and attainment of 10 percent output current in the photodetector.

A dichroic mirror, also known as a dichroic beamsplitter or interference filter beamsplitter, is an optical device that selectively reflects or transmits light based on its wavelength. Dichroic...

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...

A diffraction grating is an optical component consisting of a surface with a periodic structure of equally spaced, parallel grooves or rulings. These rulings act as an array of closely spaced slits...

Light emitted by one or more sources and characterized by a high degree of scatter.

Use of a photoelectric receiver to sense an object's presence by detecting a small amount of the emitter's light that is diffusely reflected by the object.

An electric or electronic device that regulates the voltage going to a light source as a means of varying the intensity of the light emitted by the source.

A diode laser is a type of laser that uses a semiconductor diode as the active medium to generate coherent light. Semiconductor diodes are electronic devices that conduct electricity primarily in one...

A diode-pumped solid-state laser (DPSSL) is a type of laser system that uses semiconductor diode lasers to pump energy into a solid gain medium, resulting in the generation of coherent light. This...

Directed energy refers to a type of energy that is emitted and transferred in a controlled direction. The term is often associated with military and technological applications where energy, typically...

A distributed feedback laser (DFB laser) is a type of semiconductor laser diode designed to emit coherent, narrow-bandwidth light with precise control over the wavelength. It achieves this through a...

A display format consisting of small light-emitting elements arranged as a two-dimensional array. Various elements are energized to depict a character. The typical matrix is 5 x 7 dots.

An edge-emitting light-emitting diode is a type of LED structure where light emission occurs primarily along the edge of the semiconductor chip rather than from the surface. Edge-emitting LEDs are...

Radiation emitted from vibrating charged particles. A combination of oscillating electrical and magnetic fields that propagates through otherwise empty space with the velocity of light. This constant...