Photonics Dictionary

A sensor generally used for infrared imaging. It consists of two chambers separated by a thin, blackened membrane. An infrared image is formed on the membrane by a lens or mirror and produces...

A means of determining a prism's index of refraction by placing the prism so that its emergent face is perpendicular to the incident beam. This arrangement permits the determination of the prism's...

A femtosecond laser is a type of laser that emits ultrashort pulses of light with durations on the order of femtoseconds, where one femtosecond is equal to 10-15 seconds. These lasers are capable of...

A grating used as a reflectance filter, particularly in the far-infrared. Small plane gratings, blazed for the wavelength of the unwanted radiation, are produced for this purpose.

A filter, partially opaque to near-ultraviolet, visible and infrared radiation, that may be made by exposing and processing photographic film. Such materials are almost equally opaque to radiation of...

The optical form of the crystal fluorspar, calcium fluoride, that is utilized for its low optical dispersion, its low refractive index, and its transparency to infrared and ultraviolet radiation.

An infrared imaging device composed of a detector array and readout electronics. It may include a cryogenic cooling system. The assemblies are used in meteorological and surveillance satellites,...

The application of ultraviolet, x-ray, infrared and conventional photography to law enforcement.

A free-electron laser (FEL) is a type of laser that generates coherent, high-intensity electromagnetic radiation by using a beam of accelerated electrons as the lasing medium. Unlike traditional...

A frequency comb is a precise and regular series of equally spaced spectral lines, or frequencies, that are generated with great accuracy. The term "frequency comb" is often associated with the Nobel...

A GaAlAs laser is a type of semiconductor laser diode that emits light in the near-infrared region of the electromagnetic spectrum. It is composed of layers of gallium, aluminum, and arsenic, hence...

Gallium arsenide phosphide (GaAsP) is a semiconductor alloy composed of gallium (Ga), arsenic (As), and phosphorus (P). It is commonly used in the fabrication of optoelectronic devices, particularly...

A technique for measuring the concentration of any gases. Identical infrared beams are alternately chopped, one passing through a reference cell and the other passing through a cell with the gas...

One of the first lasers to find practical application. Generally, the pumping mechanism is an electric discharge, although some high-power forms employ chemical reaction or gas compression and...

A type of glass used in near-infrared optical components, in which germanium is used as a cation instead of silicon.

A crystalline semiconductor material that transmits in the infrared.

Germanium crystal refers to a crystalline form of the element germanium (Ge), which is a metalloid and semiconductor commonly used in various electronic and optical applications. Germanium crystals...

A noncrystalline, inorganic mixture of various metallic oxides fused by heating with glassifiers such as silica, or boric or phosphoric oxides. Common window or bottle glass is a mixture of soda,...

A lamp designed to emit a large amount of infrared radiation; used in applications requiring heat.

In reference to infrared, emissions that are like radio waves but that have a higher frequency.

A glass filter that transmits visible light while absorbing infrared energy (heat).

A guided missile that uses an infrared sensor to detect and home in on an enemy target. The missile is guided by the high infrared emissions produced by a target, such as the heat from an aircraft or...

The decrease in effect in developable density on a photographic plate formed by a second exposure to radiation having a longer wavelength, usually red or infrared.

An infrared-transmitting optical fiber with a hollow core; it can be square, round or rectangular in cross section. Capable of carrying high laser power but subject to high bending losses.

An infrared device used in satellites and rockets to determine a heat horizon for the Earth at altitudes (above 200 miles) where the visible horizon cannot be discerned. The device scans the infrared...

A method of manufacturing polycrystalline infrared-transmitting optical fiber by heating a single halide crystal billet and forcing it through a die.

A mirror with a coating that reflects infrared radiation and transmits visible light.

A hyperspectral imaging camera is a sophisticated imaging device capable of capturing and processing data across a wide range of wavelengths within the electromagnetic spectrum, typically from...

An electron tube that employs electromagnetic radiation to produce a visual replica of an image produced on its cathode. Electrons ejected from the cathode by the incident radiation are accelerated...

A semiconductor material that is used as an infrared detector for light up to 5 µm in wavelength.

An InGaAs (indium gallium arsenide) camera is a type of imaging device that utilizes InGaAs sensors to capture images in the near-infrared (NIR) spectrum. InGaAs is a semiconductor material that is...

Indium phosphide (InP) is a compound semiconductor material composed of indium (In) and phosphorus (P). It belongs to the III-V group of semiconductors, where elements from groups III and V of the...

An InGaAs photodiode refers to a photodetector device that is constructed using a semiconductor material composed of a combination of indium (In), gallium (Ga), and arsenic (As). The term InGaAs...

A semiconductor diode operating in either a coherent or incoherent mode that is used as a near-infrared or visible source in triggering light-activated devices.

An infrared detector mounted directly on the cold finger of the Dewar cooler rather than at the interface of Dewar and cooler, resulting in decreased size and power consumption and greater...

A filter that transmits infrared and ultraviolet but is opaque to visible radiation.