Photonics Dictionary: K

An eyepiece consisting of a planoconvex field lens and a cemented doublet as the eye lens.

A cell filled with a transparent material that, when placed in a strong electrical field, exhibits double refraction. Since the two polarized elements of an incident light beam travel at different...

The Kerr effect, named after the physicist John Kerr who first observed it in 1875, is a nonlinear optical phenomenon where the refractive index of a material changes in response to an applied...

The process of binding or attaching larger metal sheets by laser welding. The effect is generated by higher power densities which, while creating a larger weld, produce a vapor that is penetrated by...

A type of geometrical distortion that brings about a trapezoidal display of a nominally rectangular picture. Usually produced when a picture is projected abnormally to the screen.

In the SI system, prefix meaning one thousand, 103.

A cathode-ray tube that serves as a picture tube in a television receiver. The signal representing the picture intensity is transmitted to the electron gun grid so that the beam intensity varies with...

Lens which, by altering the phase, efficiently images through a holographic process.

For any point on a thermal radiator, at thermal equilibrium and for each wavelength, the emissivity in any direction is equal to the absorptance for radiation from the same direction.

An imaging device originally created to image whole mouse brain volumes at microscopic resolution. The main component of the instrument is an automated microtome and microscope capable of producing...

A visual, single-unit spectrophotometer with a biprism and a Wollaston prism. The Wollaston prism polarizes coincident images of the two halves of the entrance aperture.

Westinghouse trade name for an alloy of iron, nickel and cobalt, which has the same thermal expansion as glass and therefore is often used for glass-to-metal or ceramic-to-metal seals.

Astronomical detector consisting of a photocathode isolated from the target by a coin value from which electrons are focused on a nuclear emission, producing tracks on the emission. Track density can...