Photonics Dictionary

That radiation characterized by wavelengths ranging from 0.2 to 0.3 µm in the electromagnetic spectrum.

Radiation whose spectrum runs between 100 and 300 nm. Any work with these wavelengths requires evacuated equipment.

Ultraviolet-C (UV-C) refers to a specific range of ultraviolet radiation with shorter wavelengths than those of visible light. UV-C radiation spans the electromagnetic spectrum with wavelengths...

An absorption peak refers to a sharp increase or spike in the absorption of electromagnetic radiation at a particular wavelength or energy level. It is a distinctive feature in the absorption...

Glass designed to absorb most infrared and ultraviolet radiation while transmitting most of the visible region.

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...

Attosecond-pump attosecond-probe spectroscopy (APAP) is an advanced technique in ultrafast spectroscopy that allows scientists to study the dynamics of electronic processes occurring on extremely...

Radiation from the invisible (usually ultraviolet) region of the spectrum.

Glass that transmits near-ultraviolet radiation but is opaque in the visible region. Also known as woods glass.

The use of chemicals or radiation to induce a desired change in a substance; e.g., some optical adhesives are set by exposure to ultraviolet light and are said to be UV-curing.

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...

A detector array refers to a collection of individual detector elements arranged in a two-dimensional grid or matrix format. Each element within the array is capable of detecting electromagnetic...

A discharge lamp filled with deuterium to produce high-intensity ultraviolet radiation for use in spectroscopic analysis.

An arc lamp whose carbon electrodes are enclosed in a transparent chamber, resulting in an arc that is steadier, lasts longer and emits more ultraviolet radiation.

In ultraviolet and fluorescence photography, the term applied to the filter used in the photographic system and with the exciting source to screen out ambient radiations and to transmit the exciting...

Extreme ultraviolet (EUV) refers to a specific range of electromagnetic radiation in the ultraviolet part of the spectrum. EUV radiation has wavelengths between 10 and 124 nanometers, which...

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 photographic recording of a subject that exhibits luminescence only for an extremely short time (10-8 s) after the exciting source is removed. In the process, the subject may be illuminated by...

A type of optical microscope that allows the specimen being viewed to be irradiated by ultraviolet, violet and occasionally blue radiation, causing the specimen to fluoresce.

A fluorescent screen refers to a phosphorescent or fluorescent-coated surface that emits visible light when exposed to other forms of electromagnetic radiation, such as x-rays or ultraviolet light....

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.

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...

Germicidal ultraviolet (GUV) refers to a specific range of UV radiation that has disinfectant properties capable of killing or inactivating microorganisms, including bacteria, viruses, and fungi. The...

A device that detects and measures the quantity of exposure to nuclear radiation. It uses a special glass rod that fluoresces when placed under ultraviolet radiation after its exposure to nuclear...

The light flash that occurs when an electrical field is applied to a phosphor already excited by ultraviolet radiation.

A filter, used in photography, that absorbs the ultraviolet and extreme blue violet radiation scattered by atmospheric haze.

The ionization and spark emission due to exposure to ultraviolet radiation.

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

Electromagnetic radiation detectable by the eye, ranging in wavelength from about 400 to 750 nm. In photonic applications light can be considered to cover the nonvisible portion of the spectrum which...

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...

Fiber that emits luminescent radiation excited by ultraviolet, x-ray or high-energy particles.

The hydrogen-derived, ultraviolet radiation running from 1216 to 512 A, discovered by Theodore Lyman in 1914.

An acronym for microwave amplification by stimulated emission of radiation. Predecessor to the laser, the maser or 'microwave laser' was the first device to produce coherent electromagnetic waves,...

A lamp that has mercury in a tube or bulb that has first been evacuated. The electricity travels through the vapor between the electrodes and produces a blue-green light that is rich in ultraviolet...

A spectrometric instrument that detects radiation simultaneously in multiple channels, sorts it spectrally from the deep ultraviolet to the infrared, digitizes the information and stores it for...

A multiline laser system refers to a type of laser that is capable of emitting multiple discrete wavelengths or spectral lines simultaneously. Unlike single-line lasers, which produce radiation at a...

A light source, such as the sun or an incandescent lamp, that freely penetrates ordinary glass bulbs and emits in the near-ultraviolet (wavelengths ranging from about 300 to 400 nm). A mercury vapor...

An optical clock is a highly precise and advanced timekeeping device that relies on the oscillations of electromagnetic radiation in the optical or ultraviolet part of the electromagnetic spectrum....

The process by which an atomic system changes from one energy level to another by either the emission or absorption of visible, infrared or ultraviolet radiation.

Any organic substance, that when dissolved in appropriate liquid based solvents will absorb and emit electromagnetic radiation in the near ultraviolet, visible and near infrared spectral regions....

A chemical substance that exhibits fluorescence when excited by ultraviolet radiation, x-rays or an electron beam. The amount of visible light is proportional to the amount of excitation energy. If...

The term photochemical pertains to chemical processes or reactions that are initiated or influenced by the absorption of light. Photochemical reactions involve the interaction of light, often in the...

Photochromic refers to a property exhibited by certain materials, typically organic compounds or dyes, which undergo reversible changes in color when exposed to light. Specifically, photochromic...

Phototherapy is a medical treatment that involves the use of light to treat various conditions, particularly those related to the skin or mood disorders. There are different types of phototherapies,...

A lamp with a quartz envelope that transmits radiation generally rich in the ultraviolet.