Type

Browse by Letter

Trioptics GmbH - Worldwide Benchmark 4-24 LB

PI Physik Instrumente - Semiconductor Applications 5/24 LW HP

33 terms

Photonics Dictionary: A

Clear All Filters x radiation x A x
accessible radiation

Electromagnetic radiation present upon the open aperture of the source within an operating environment.

actinic radiation

Electromagnetic energy that is capable of producing photochemical activity.

annihilation radiation

Gamma ray radiation released when matter and antimatter, such as electron and positron, unite and eliminate each other, transforming completely into energy. The resulting gamma ray spectrum depends...

actinochemistry

The study of chemical changes produced by radiation.

ablation threshold

The minimum energy required to induce atomic and molecular separation or displacement due to incident intense laser irradiation.

absorption peak

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...

accessible emission

The present radiation level within a laser or electromagnetic radiation operating area.

actinic glass

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

actinism

The creation of a chemical reaction in a substance when radiation is directed to it.

actinometer

A device that measures the intensity of photochemically active radiation, particularly from the sun. One form of this instrument determines the fluorescence initiated by the radiation.

active region

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

adiabatic laser colorimetry

Method for studying absorption coefficients of low-loss materials, in which a sample is allowed to come to thermal equilibrium with its surrounding blackened enclosure. The sample is irradiated with...

air dose

A quantitative measure of the amount of radiation given off by an instrument, expressed in roentgens per unit of free air.

amplified spontaneous emission

Broadband radiation emitted by a laser that does not transmit through the optical element. It can be removed by filtering.

analog thermogram -> thermogram

Also known as analog thermogram. The resultant photograph, illustrating, in tones ranging from black to white, the spatial relationship of the infrared radiation temperatures of the different details...

Angstrom compensation pyrheliometer

A system used for measuring direct solar radiation.

angstrom

An angstrom, symbolized by the Ångström or Å, is a unit of length used to express atomic and molecular dimensions. It is equal to 0.1 nanometers or 1 × 10-10 meters. The...

antibleaching

Characteristic of an absorber in the IR region, whereby absorption increases as a direct function of the intensity of the incident, continuous radiation.

antiguide

A waveguide that has a core with a lower refractive index than the refractive index of the cladding. This structure can limit the power of the transmitted beam by removing unwanted radiation, for...

aperture

An opening or hole through which radiation or matter may pass.

aperture imaging

The formation of an image by a pinhole aperture that transmits radiation, such as gamma radiation.

arc flash

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...

arc light source

In present usage, especially for spectroscopic identification, an arc between electrodes that serves as a radiation source. Gas tubes that contain mercury vapor and mixtures of helium, neon and argon...

ARM

antiradiation missile

astronomical photography

The use of photographs to record astronomical objects and phenomena for purposes of physical observation and measurement of motion, radiation and spectra.

astronomy

The scientific observation of celestial radiation that has reached the vicinity of Earth, and the interpretation of these observations to determine the characteristics of the extraterrestrial bodies...

atmospheric optics

The analysis of the properties of radiation, such as light, when acted upon by variations in the atmosphere. Blue and red skies, along with ice halos, glories, coronas and rainbows can all be...

atmospheric window

A range of wavelengths within which radiation transmitted through the atmosphere suffers relatively little absorption by atmospheric gases.

atomic absorption spectrometer

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...

atomic absorption spectroscopy

The analysis of the atomic structure of a sample by means of a source radiation that is absorbed and emitted by the sample with lines corresponding to the number and arrangement of atoms. Generally a...

atomic fluorescence spectroscopy

The analysis of fluorescence emitted by discrete atoms, in flames, that have absorbed radiation from an external source. It is used to study the physical and chemical processes that arise from...

attosecond-pump attosecond-probe spectroscopy

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...

Auger effect

The radiation-free transition that takes place within an ion, in which inner-shell vacancies in neutral atoms are filled by outer-shell electrons, thereby transferring energy to other electrons,...

Photonics DictionaryA

We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.