Photonics Dictionary

A high-brightness, short-duration source in which low-pressure gas initiates the discharge to vaporize material from the tube wall, leading to a high-pressure discharge of ionized wall material.

A glow discharge lamp consisting of a cold cathode and a mixture of inert gases. The intensity of illumination varies with the applied signal voltage. This lamp was commonly used as a source of...

The luminosity that remains in a rarefied gas after an electrodeless discharge has traversed the gas.

The electric arc that is a particular discharge between two electrodes in a gas or vapor which is characterized by high cathode densities and a low voltage drop.

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...

The area of low-level luminance lying between the cathode and the negative glow in a glow-discharge, cold-cathode tube.

The apparent luminosity or glow that immediately envelops the cathode in a gas-discharge tube operating at low pressures. The glow increases as the pressure decreases.

Also known as cathode rays. Formerly, this term described a stream of electrons emitted from the cathode of a gas-discharge tube during its bombardment by positive ions. It also describes any stream...

In a gas, an electrical discharge that has no luminance.

A lamp that uses the transmission of an electric current through a gas or vapor to produce illumination. Neon, mercury and argon lamps are examples of electric-discharge lamps.

Approximation of a system of thermal equilibrium formed by the distribution of the kinetic energies of electrons in a gas discharge to which a temperature value is frequently ascribed. The average...

A small xenon-filled tube with metal electrodes fused into the ends. The gas flashes brilliantly when a condenser is discharged through the tube. The duration of the flash is primarily dependent upon...

An excimer laser is a type of ultraviolet laser that emits short pulses of light in the ultraviolet spectrum. The term excimer is derived from excited dimer, reflecting the nature of the gain medium...

The lowest anode voltage at which a gas tube can sustain a discharge.

A fiber optic spectrometer is a device used for measuring the spectral content of light. It utilizes optical fibers to transmit light from a source to a spectrometer unit, where the light is...

The conduction of electricity in a gas as a result of the ions generated by collisions between electrons and gas molecules.

A display device that contains an inert gas that gives off orange light when a high voltage is applied to ionize 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 specific gas-filled tube designed to illustrate the luminous effects of discharges through rarefied gases.

An electric discharge in a low-pressure gas having a low-current density and a space potential near the cathode that is much higher than the ionization potential of the gas but less than its sparking...

A helium-neon (HeNe) laser is a type of gas laser that emits visible red light at a wavelength of 632.8 nm. It operates based on the principle of stimulated emission of photons from excited helium...

An infrared light source is a device that emits light in the infrared spectrum, which lies beyond the visible spectrum of light. Infrared light has longer wavelengths than visible light and is...

A nonluminous area around a negatively charged probe that is inserted into the positive column of an arc or glow discharge.

Laser active elements typically refers to the substances or materials within a laser system that play a critical role in the amplification of light through the process of stimulated emission. These...

A laser, which stands for "light amplification by stimulated emission of radiation," is a device that produces coherent and focused beams of light through the process of optical amplification based...

A nanotube, also known as a nanotubule or simply a tube-like structure, is a nanoscale cylindrical structure composed of various materials, including carbon, boron nitride, or other compounds....

An electron tube containing neon gas that uses the transmission of an electric current through the gas to ionize the neon and produce a luminous red discharge.

A glow discharge tube placed on an insulating rod to detect the presence of high-frequency radiation in the vicinity of a transmitter. The tube indicates the presence of the radiation by the glow...

A standard source of high-charge-state ions for accelerators that has an external magnetic field oriented perpendicularly to the two cathode faces. Also called Philips ionization gauge.

A spectroscopic process that detects and analyzes the discharge from an extrinsic surface with less than bandgap light. This method may determine the extrinsic surface-state energy levels of a...

A type of flat panel display made up of a layer of gas between two glass plates. The glass is coated with parallel conductors that form cells which, when energized, produce a gas discharge that makes...

A gas laser in which the electrodes are mounted perpendicular to the optical resonator.

A compact high-pressure light source in which an electrical discharge between electrodes spaced no more than 12 mm apart occurs in a xenon or other gas medium, providing a visible light resembling a...

A discharge tube filled with various gases and used as a source in spectroscopy.

A device that produces brief flashes of light for observing the behavior of an object during a short interval. One of the most effective means for accomplishing this is a gaseous tube energized by...

An arc discharge tube having a grid that is used to start the discharge through an atmosphere of inert gas or vapor at low pressure.

Abbreviated TEA CO2 laser. A gas laser that provides shorter pulses and higher peak powers than conventional CO2 lasers. The electrical excitation pulse occurs transversely to the optical axis...