Photonics Dictionary: I

In a heterodyne optical receiver, the frequency that is the difference between that of an incoming laser signal and that of the local oscillator laser. Also called beat frequency.

In an optical system with a series of lenses, images formed prior to the final focal plane.

A nonoptical surface, within lenses and lens mounts, that contributes largely to flare by reflecting light into the image space. As a result, such surfaces, so located, are finished with a dull...

A material often used in the construction of optical instruments because of its low coefficient of thermal expansion (0.9 x 10-6/ °C).

A method of fabricating a graded-index optical waveguide by means of an ion exchange process.

A laser in which the transition involved in stimulated emission of radiation takes place between two levels of an ionized gas. The gases are electrically excited in a container called a plasma tube,...

Ion-beam sputtering (IBS) is a physical vapor deposition (PVD) technique used for depositing thin films onto substrates. It involves bombarding a target material with a beam of energetic ions,...

Indication of emission brightness with degree of emission from an optical source.