Photonics Dictionary: K

In an interlaced scanning electro-optical system such as television, the system resolution will be less than the number of active scan lines because of the random phase nature of the object being...

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

The SI unit of temperature equal to 1°C. See absolute temperature scale.

A simple form of astronomical telescope that uses a fixed objective and a focusable eyepiece. The objective forms an intermediate image in the instrument, resulting in an image that appears upside...

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 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...

Analysis of the reflection spectrum that allows the determination of the experimental dielectric function.

A two-flux theory in which the radiation is assumed to be composed of two oppositely directed radiation fluxes through a continuous medium. The theory has been widely used to relate the total diffuse...

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...

A Kerr soliton refers to a specific type of soliton, a self-reinforcing wave packet, that arises in nonlinear optical systems due to the Kerr effect. The Kerr effect is the phenomenon where the...

An array of spectral lines formed when a beam of electrons, striking a crystalline solid, is scattered. It is used in the analysis of the crystal structure.

A mount for an optic element or optics assembly, designed so that all six degrees of freedom are singly constrained. This assures that movement will be prevented, while stress will not be introduced...

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...

An atmospheric nonlinear process unique to CO2 laser wavelengths, whereby CO2 absorbs 10.6-µm radiation and the CO2 molecules in the (100) vibrational state are excited to the (001) level, and...

A computer-generated kinoform used for data processing because of its use of incoherent light and its wide field of view, which facilitates parallel processing of two-dimensional data.

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.

A thermionic tube that has a velocity-modulated electron stream and that may be used as a microwave amplifier or oscillator.

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...

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...