Photonics Dictionary: Z

The intensity regulation of a cathode-ray tube by alteration of the grid-cathode voltage.

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...

Broadening of a spectrum that results from the influence of a magnetic field.

The splitting of energy levels of an atom, ion or molecule because of a magnetic field.

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.

In the SI system, prefix meaning 10-21. (z).

The introduction of a filter into an imaging system to implement a phase contrast for an intensity mapping of a pure phase image.

A highly flame-retardant material used to jacket fiber optic cables, especially on shipboard applications.

In an interference pattern, that point where there is no difference between the optical paths of the interfacing wavefronts.

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...

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

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

The difference in electrokinetic potential between the stationary liquid connected to a solid phase surface and the mobile portion of the liquid's diffuse layer.

In the SI system, prefix meaning 1021. (Z).

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

A two-fiber optical cable containing two single-fiber cables that are connected by a strip of jacket and that can easily be separated from one another for the installation of optical connectors.

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.

The sunlight that extends to the earth after scattering from other solar bodies, mostly from meteorite dust of radii equaling 10-3 cm.

Spherical or chromatic aberration in a lens having a wide aperture. It is present because the refracting power varies for different zones concentric at the axis. This is the residual when the lens...

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.

Also known as zonal axis. The axis positioned through the center of a crystal that is parallel to a zone edge.

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...

1. In a polished surface, concentric waves that appear as zones in Newton's rings when a test glass is applied. 2. An arrangement of crystal faces that come together in a series of edges, all of...

To control, by magnifying or reducing, the size of a televised image, either electronically or optically.

An optical system of variable focal length, the focal plane remaining in a fixed position. This result is achieved by moving some of the components of the system along the lens axis, other components...