Photonics Dictionary: P

The transmission of data in groups (packets) of information~comma~ each handled as an aggregate.

The production of a positron-electron pair by a photon having energy greater than one mega-electron-volt, whereby some of the photon energy is converted to the rest mass of the pair.

A camera designed to form a continuous record of an expansive section of the horizon. The typical panoramic camera is mounted to rotate about a vertical axis. A slit opening in the film plane and the...

The image distortion produced by a panoramic camera with a swinging lens or a swinging mirror in front of a fixed lens. The magnification is greatest in the center and diminishes to each side in the...

An array of lines in the infrared region of the emission spectrum of atomic hydrogen. Their wave numbers are expressed by the equation: where represents the wave number in the reciprocal centimeters,...

Typically represented by the Greek letter μ, magnetic permeability is the measure of a material's ability to generate and sustain a magnetic field within itself when an external magnetic field is...

The term perovskite refers to a specific crystal structure commonly found in various materials. Perovskite structures have a cubic arrangement of oxygen ions, forming a framework within which other...

A type of matched filter that responds only to the phase of incoming light; the output has a much greater intensity than that of a classical matched filter, which responds to phase and amplitude. The...

The use of photoelectric sensors to detect and measure the intensity of a light source. This application, as compared to human observation, results in higher speeds of operation, a greater...

Photogrammetry is a technique used to obtain accurate three-dimensional measurements of objects and environments through the analysis of photographs or imagery. It involves extracting information...

A type of computer in which the electronic circuits, which process data serially, are replaced by photonic circuits capable of parallel processing and thus of much greater speed and power. Where the...

A solid-state device similar to an ordinary transistor except that incident light on the PN junctions regulates the response of the device. It offers built-in gain and a greater sensitivity than that...

Photovoltaic (PV) refers to a technology that converts sunlight directly into electricity using semiconductors. The term "photovoltaic" is derived from the words "photo," meaning light, and...

A vacuum gauge designed to measure very high degrees of vacuum by thermal conduction.

A pixel, short for "picture element," is the smallest controllable element of a digital image or display. It is a fundamental unit that represents a single point in a raster image, which is a grid of...

The property exhibited by certain birefringent crystals in which the degree with which they transmit polarized light is different, depending on whether the ray is ordinary or extraordinary. An...

A lamp, usually incandescent, that has a very compact filament, permitting a greater concentration of emitted light, aided by the use of small apertures and appropriate reflectors.

A polariton is a quasiparticle resulting from the strong coupling between photons (light particles) and certain types of excitations in a material, such as electronic excitations (electrons and...

A substance that transmits the infrared, but which is too delicate or fragile to be used in the form of a single crystal. Instead, the pure material is finely ground, pressed to the required shape,...

A set of three colored lights which, when mixed, give the sensation of white light. The set used in color television, for example, is red, green, blue (RGB).

A pair of telescopes with prismatically erected images, mounted side by side with the eyepieces at the interocular distance of the observer. This separation is adjustable with a convenient millimeter...

Acronym for profile resolution obtained by excitation. In its simplest form, probe involves the overlap of two counter-propagating laser pulses of appropriate wavelength, such that one pulse...