Photonics Dictionary: P

The micrometer-size depressions that store data digitally in an optical data storage medium.

Pitch for polishing mixed with other materials to give it the right viscosity so that it will follow the fine-ground lens surface and yet maintain contact at all times.

Pixel binning, also known as pixel merging or pixel combining, is a technique used in digital imaging and camera technology. It involves the combining or grouping of adjacent pixels on an image...

Pixel pitch refers to the distance between the centers of two adjacent pixels on a display screen or imaging sensor. It is typically measured in millimeters and is a crucial specification in...

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...

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...

The formula describing the spectral radiant emittance of a perfect blackbody as a function of its temperature and the wavelength of the emitted radiation. where Wλ equals radiation...

A transmission or reflecting grating with a flat or plane surface requiring a lens or concave mirror to focus the spectrum.

An imaginary plane dividing a body into two parts so that each part is the precise mirror image of the other in the plane of symmetry.

A camera system used for microphotography in which the document to be recorded is on a flat bed, perpendicular to the lens axis. The camera head is located above the copyboard on a column and may be...

A manufacturing process used to construct substrates for large optical components. Used with IR materials, planform bonding permits the joining of several smaller pieces to be used in place of a...

A lens or mirror surface that is perfectly flat.

A plasma accelerator is a type of particle accelerator that uses electric fields and magnetic fields to accelerate charged particles, typically electrons or ions, by exploiting the motion of charged...

The use of a plasma to induce the formation of oxides in the production of graded-index optical fibers.

Operates with light collectively emitted by the recombination of free electrons and ions in the plasma state.

Plasma's ability to stop the transmission of laser light.

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...

Plasmonics is a field of science and technology that focuses on the interaction between electromagnetic radiation and free electrons in a metal or semiconductor at the nanoscale. Specifically,...

The direct cladding used for fused silica cores to create large numerical aperture fibers and used as overcoats to glass-clad fibers to reduce microbend loss and increase mechanical protection.

Plastic optical fiber (POF) is a type of optical fiber made from transparent plastic, typically polymethylmethacrylate (PMMA) or polycarbonate. Unlike traditional glass optical fibers, which are made...

Plastic optics refers to optical components or systems that are made from transparent plastic materials, as opposed to traditional optical components made from glass or other materials. Plastic...

A semiconductor material used in photodetectors, sensitive in the infrared up to 5 µm.

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 mixture of ionized gas and metal vapor generated by impingement of the laser beam onto a material being welded or a weld joint. The plume causes absorption and/or scattering of the incident laser...

A transparent lead-lanthanum zirconate titanate ceramic with optical qualities that can be controlled by applying voltages to thin plates of the material.

The transition boundary between P-type and N-type materials in a semiconductor.

Discharge that results when a doped semiconductor crystal with a PN junction is charged with a low-voltage direct current. The dual process depends on excitation caused by electrical energy...

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.

The point spread function (PSF) is a fundamental concept in imaging that describes the response of an imaging system to a point source or point object. It characterizes how a single point of light is...

A crystal diode whose rectifying activity is determined by the touching of the crystal to a finely pointed wire surrounded by a material of opposite type.

A device used in solar systems to direct mirror-reflected sunlight to a heat absorber and heat-driven engine, which turns a generator to produce electricity.

A method of producing magnified images by x-rays. The specimen is placed close to a point source of x-rays; the magnification achieved is the ratio of source-image to source-object distance....

A device attached to the end of an alignment telescope that detects and calculates a plane mirror's rotation axis that is perpendicular to the line of sight. The device is adaptable for evaluation of...

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.

The determination of a substance's identity or quantity through the analysis of its optical rotation. For example, the examination of crystals and polymers under polarized infrared radiation is very...

A combination of a polarizer and an analyzer that is used to detect birefringence or rotation of the plane of polarization of materials placed between them. Useful for the determination of stress...

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...

Polarization refers to the orientation of oscillations in a transverse wave, such as light waves, radio waves, or other electromagnetic waves. In simpler terms, it describes the direction in which...

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.

A photometer having a pair of Nicol prisms introduced into the beam from the brighter of two sources to be compared. Turning one of these polarizers reduces the beam to equality with the beam of the...

Capability requirement for optical switches for transmission lines to process arbitrarily polarized light because of the rapid changes in the polarization state of light propagating in the fibers.