Photonics Dictionary

A small mass spectrometer used to find leaks in a vacuum system by detecting the presence of helium. Using a magnetic deflection device that is permanently tuned to helium, it is capable of detecting...

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...

A laser, usually employing helium-neon or other gases as the active medium, used for alignment in industrial applications.

A positively charged particle emitted from the nucleus of an unstable isotope, characterized by two protons and two neutrons. Quantitatively, the equivalent of a helium atom's nucleus.

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...

A vacuum pump in which pressure is reduced by condensing gases on surfaces cryogenically cooled to about 20 K (liquid hydrogen) or 4 K (liquid helium).

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...

An infrared detector is a device that is used to detect and measure infrared radiation, which lies beyond the visible spectrum of light. These detectors are utilized in various applications,...

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 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...

An instrument used to detect radioactive materials: alpha particles or helium nuclei; beta particles or free electrons; and gamma rays, which are x-rays of very short wavelength. They may be detected...

Although low in sensitivity (approximately 10-7 m for helium-neon lasers), this holographic technique permits quantitative assessment of entire vibratory patterns of given structures in a single...

Van der Waals forces refer to the attractive or repulsive forces between molecules (or parts of molecules) that arise from fluctuations in electron distribution. These forces are relatively weak...

An instrument for eye surgery that directs intense xenon arc light through the transparent cornea lens to the retina where absorption by the pigment epithelium and the choroid produces heat and...