Photonics Dictionary: Z

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...

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 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.

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 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...