Photonics Dictionary: Z

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

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...

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

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 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...

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

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.

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.

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°.

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...

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.

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.

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

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...

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...