Photonics Dictionary: B

A ground-based navigation beacon that emits pulsed signals which are picked up by aircraft making an instrument (blind) approach in landing. The signal is transmitted to the aircraft's L-scan...

A filter that suppresses a given range of frequencies, transmitting only those above and below that band. Also called bandstop filter.

The angular width of a radiation beam. With respect to a conical beam of light, it is the vertex angle of the cone. The beamwidth is a measure of the rate of divergence or convergence of a light...

A defect on or in an optical element that does not appreciably impair the function of the surface.

A biomarker, short for biological marker, refers to a measurable and quantifiable indicator of a biological condition, process, or response. Biomarkers can be substances or characteristics that are...

A blackbody source, often simply referred to as a blackbody, is a theoretical or practical physical object that absorbs all electromagnetic radiation incident upon it and emits radiation in a...

A piece of glass, quartz or other transparent material formed roughly by molding or cutting into the approximate shape and size of the finished part.

Blaze height typically refers to a parameter in the context of diffraction gratings, which are optical devices consisting of a series of closely spaced parallel grooves or slits. The blaze height is...

An adhesive used to affix optical elements to an approximately shaped body -- usually of cast iron.

A constant equal to the universal gas constant divided by the Avogadro number. It is approximately equal to 1.38 x 10-23 J/K and is commonly expressed by the symbol k.

A Bose-Einstein condensate (BEC) is a state of matter that forms at temperatures close to absolute zero. It is named after Satyendra Nath Bose and Albert Einstein, who independently predicted the...

In avalanche photodiodes, the point at which an increase in the reverse bias voltage causes the current gain to approach infinity.

A high-frequency pulse-rate laser with an output limited by the heat capacity of the laser medium. Instead of having continuous cooling, the laser operates until the medium reaches a maximum...