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.

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

A device that responds to incident light but does not generate light.

A passive optical network (PON) is a telecommunications network architecture that uses optical fibers and passive optical components to provide high-speed broadband services to end-users. In a PON...

An LCD that has pixels with no internal drive transistors.

An OLED display formed by creating an array of OLED pixels connected by intersecting anode and cathode conductors arranged in rows and columns. Electrical power is passed through selected pixels by...

The wavelength at which a lamp radiates its highest intensity.

A type of glass that includes phosphorus pentoxide and that, unlike silica-based glass, is resistant to hydrofluoric acid.

The electron emission from a substance or instrument whose surface has been bombarded by a suitable amount of radiation.

An electronic tube instrument in which the anode current varies with the intensity of light incident on the cathode.

A photometer that uses a photoemissive tube to detect and measure light. See photoelectric photometry.

In digital image processing, a subcategory of frame processing that treats each pixel in terms of its relationship to adjacent pixels. Perceived brightness trends facilitate spatial filtering.

Low-insertion-loss fiber coupler fabricated from a sheet of light-sensitive material laminated onto a fused quartz substrate and exposed through a suitable mask. After development of the plastic...

Plasmon ion-assisted deposition (PIAD) is a technique used in thin-film deposition processes, particularly in the production of optical coatings. This method combines two key processes: plasmon...

In digital image processing, a subcategory of frame processing that transforms pixel brightness and contrast through use of a mapping function. Point processing can be single-image (simple contrast...

A stationary noise that occurs for visible light photodetection when a steady light source, such as a heterodyne reference beam or high background light, dominates the signal.

In passive optical components, loss that varies as the polarization state of the propagating wave changes. Expressed as the difference between the maximum and minimum loss in decibels.

The process of forming a polisher by pressing it with an optical surface.

A medical imaging device that uses a ring of crystal/photomultiplier tube assemblies encircling the patient to detect gamma rays emitted by positrons colliding with electrons.

A crystalline material with a high electro-optic coefficient, capable of operating at short wavelengths, with applications in laser, optical disc, printing and microwave systems.

A blank having basic surface curves attained by forming heat-softened glass that is pressed in a mold.

Injecting a gas (usually nitrogen) with a very low moisture content into the body of an optical instrument to create a positive internal pressure. This prevents the entrance of moisture, which could...

A photographic camera designed to produce reproduction film of visual information (pictures, line drawings, graphs) for printing purposes.

The collection and analysis of data relevant to monitoring the rate and quality of industrial production, either continuously or in batches. Corrections can be made manually or automatically, via a...

A lens that is symmetrical and designed to work between 1:1 and about 4:1. It covers a field of about ±20° at f/8 or f/10, and may have a focal length up to about 30 in., although the usual...

A superposition of many zone plates, each reconstructing a real and virtual point image at the appropriate locations upon illumination by a reference beam.

A means of testing the strength of optical fibers to ensure reliability, by applying stress to the fiber so that any flaws generated during manufacturing or handling result in breakage of the fiber.

A means of achieving higher peak powers and more efficient harmonic generation by narrowing the pulse width and thus increasing the frequency bandwidth of the output of CW mode-locked lasers....

In a semiconductor, the state created by the addition of a dopant that creates excess holes.

A semiconductor material in which the dopants create holes as the majority charge carrier. It is formed by doping with acceptor atoms.

The finite amount of electrical charge generated in response to incident radiation and transferred from one storage element to the next in a charge-coupled device. Each packet corresponds to a pixel...

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

1. In a photonic interconnect, the number of detectors in a given area. Detectors spaced too closely may give rise to crosstalk. 2. In the cross section of a fiber optic bundle, the ratio of fiber...

The ratio of the active core area of a fiber bundle to the total area at its light-emitting or receiving end.

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.

In interlaced television scanning, an effect in which the lines of one field fail to fall exactly within the lines of the following field, both fields comprising one frame of the picture. The lines...

Black and white film that has a wavelength sensitivity similar to that of the eye.