Photonics Dictionary: P

In imaging, the processing of pixel data in such a way that a group of pixels is analyzed at one time rather than one pixel at a time.

Parallel scanning refers to a method of acquiring data or images simultaneously from multiple sources or in parallel, rather than sequentially scanning each source one after another. This approach is...

A mode of data transmission whereby bits of information are carried simultaneously at different frequencies over a single channel.

A pair of waveguides with axes normal to the plane and that guide uniform cylindrical waves.

A device that converts data transmitted in the parallel mode to a sequence of bits at a single frequency for output in the serial mode.

In a camera or cathode-ray tube, distortion that is designated by a lateral skewing of the reproduced image.

A concave mirror that has the form of a paraboloid of revolution. The paraboloidal mirror may have only a portion of a paraboloidal surface through which the axis does not pass, and is known as an...

A ray that behaves according to paraxial equations; one that lies close to and almost parallel to the optical axis.

A prism made up of two air-spaced components. It has the ability to revert, and not invert, an image, and can be used in convergent, divergent and parallel light. May be rotated to compensate for...

A form of dispersing prism, often used in monochromators, that consists of a common right-angle prism with a 30° dispersing prism attached to each of its square faces. The spectrum formed by the...

A Peltier cooler, also known as a thermoelectric cooler (TEC) or thermoelectric module, is a solid-state device that uses the Peltier effect to transfer heat between two electrical junctions. It can...

A five-sided prism containing two reflecting surfaces at 45° to each other, and two refracting faces perpendicular to the entering and emerging beams. The deviation angle of 90° is...

A crystalline substance in which all planes are parallel, or approximately parallel.

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 photovoltaic cell, commonly known as a solar cell, is a semiconductor device that directly converts light energy into electrical energy through the photovoltaic effect. The photovoltaic effect is...

A wave whose surfaces of constant phase are infinite parallel planes normal to the direction of propagation.

A type of flat panel display made up of a layer of gas between two glass plates. The glass is coated with parallel conductors that form cells which, when energized, produce a gas discharge that makes...

1. With respect to angular subtense, a source of light, such as a star, that is very small. In a lab, a point source may be simulated by imaging a large source onto and through a pinhole, or by...

The dielectric coefficient parallel to the director in a liquid crystal display (LCD), rather than perpendicular to the director.

The chromatic resolving power of a prism is invariably stated for the case in which parallel rays of light are incident on the prism, in which the prism is oriented at the angle of minimum deviation...

A planar photocathode and a planar phosphor screen mounted in a close-spaced parallel configuration in an evacuated enclosure so that the ensemble of photoelectrons emitted from each photocathode...