Photonics Dictionary: Z

A polyethylene grating that transmits the long wavelengths and diffracts shorter wavelengths in controlled directions.

A technique for determining the nonlinear optical properties of a sample material by moving the sample through a focused laser beam and measuring changes in the beam's characteristics, such as...

A type of semiconductor diode used in voltage-limiting circuits; when voltage reaches a certain value, the device becomes a conductor.

A telescope that is fixed or has a limited degree of movement in a vertical plane; primarily used to determine the position of stars near the zenith.

A mirror that supplies equal reflectance for both the S-polarization and the P-polarization of a laser for a defined angle of incidence, usually 45°.

In a single-mode optical fiber, the wavelength that causes material dispersion and waveguide dispersion to cancel each other. In a multimode fiber, loose term for the wavelength at which there is a...

The removal of the zero-order component of the Fourier spectrum distribution of an object with a small, opaque absorber or reflector in the Fourier plane, to produce images that appear bright on a...

A grating that specularly reflects the specified long radiation wavelengths and diffracts the shorter wavelengths off in known directions, eliminating the interference of randomly scattered radiation.

A quarter- or half-wave retarder made from two plates of quartz, mica or polymer with their fast axes crossed; the difference in thickness between the two plates determines the retardance. Zero-order...

Schott Glass Technologies' trade name for a glass-ceramic material with a very low coefficient of thermal expansion.

A polycrystalline material that transmits in the infrared; it is used as a phosphor in x-ray and television screens.

A small bulb containing a conducting gas, an arc being formed between a metal ring and a tiny zirconium electrode near the center of the ring. The heated zirconium emits light, and constitutes a...

An infrared transmitting material used in the production of fluoride glasses for optical fibers.

A factor that, when multiplied by the average candlepower emitted by a light source in a specified angular zone, reveals the lumens in the zone.

A plate of glass, usually a photograph, on which there is a central spot surrounded by concentric annular zones, alternately opaque and transparent, the radii of the boundaries between the zones...