Any of a number of hard materials, such as aluminum oxide, silicon carbide, and diamond, that are powdered and carefully graded according to particle size, and used to shape and/or finish optical elements, including the endfaces of optical fibers and connectors.
Note: For finishing the endfaces of optical fiber connectors, abrasive particles are adhered to a substrate of plastic film,… (Read More →)

In communications, computer, and data processing systems, an address that directly identifies a storage location without the use of an intermediate reference, e.g., a base address or a relative address. [After Weik '96]

1. The time interval or phase difference between transmission and reception of a signal.
2. The total time between the instant a bit enters the network and the instant a corresponding bit exists the network. [T1.503-1989] [T1.507-1996]

1. Of an antenna, for a given direction and polarization, the ratio of (a) the power that would be required at the input of an ideal isotropic radiator to (b) the power actually supplied to the given antenna, to produce the same radiation intensity in the far-field region.
Note 1: If no direction is given, the absolute gain of an… (Read More →)

See thermodynamic temperature.

The ratio of the luminous flux or absorbed radiant flux to the incident flux.

In the transmission of electrical, electromagnetic, or acoustic signals, the conversion of the transmitted energy into another form, usually thermal. [After 2196]
Note 1: Absorption is one cause of signal attenuation.
Note 2: The conversion takes place as a result of interaction between the incident energy and the material medium, at the molecular or atomic level.

A spectral region in which the absorption coefficient reaches a relative maximum, by virtue of the physical properties of the matter in which the absorption process takes place. [FAA]

A measure of the attenuation caused by absorption of energy that results from its passage through a medium. [After 2196]
Note 1: Absorption coefficients are usually expressed in units of reciprocal distance.
Note 2: The sum of the absorption coefficient and the scattering coefficient is the attenuation coefficient.

1. A measure of the attenuation caused by absorption of energy per unit of distance that occurs in an electromagnetic wave of given wavelength propagating in a material medium of given refractive index.
Note: The value of the absorption index K' is given by the relation ,f01 where K is the absorption coefficient, is the wavelength in vacuum, and n… (Read More →)