Photonics Dictionary: P

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 whole-flow-field technique providing instantaneous velocity vector measurements in a cross-section of a flow that is seeded with micron-sized particles. CCD or CMOS cameras and laser light sheets...

A phase-modulated sensor is a type of sensor that uses modulation of the phase of a signal to measure changes in a physical quantity. In such sensors, variations in the phase of the signal are...

A method for remote measurement of the temperature of moving surfaces in harsh environments by using a laser to stimulate fluorescence of thermographic phosphors and then measuring the decay times by...

Photoconductive antenna (PCA) is a semiconductor element that generates or detects high-frequency electromagnetic signals. Compact PCAs based on gallium arsenide (GaAs) or indium gallium arsenide...

A photodetector, also known as a photosensor or photodiode, is a device that detects and converts light into an electrical signal. Photodetectors are widely used in various applications, ranging from...

Photoelastic equipment and supplies refer to instruments and materials used in photoelasticity, a technique used to analyze stress distribution and behavior in materials. photoelastic equipment...

A system having a photoelectric detector for the measurement of three quantities related by linear combination to tristimulus values of a sample.

The measurement and analysis of color using a photoelectric instrument having three filters with broad spectrum bands.

A device used to count objects that pass a given point by allowing each object to obstruct a beam of light falling on a photocell. Slow counting rates can be recorded by a mechanical counter, but...

A device consisting of a microammeter, a photovoltaic cell and a battery. It is used for the measurement of scene brightness and the determination of correct exposure for photographic processes.

A system that consists of a spectrophotometer with a photoelectric detector for measurement of radiant energy.

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 form of photometric measurement, often used with light sources that are transparent or fluctuating, in which a photographic plate is used to obtain a record of a source's relative intensities over...

The use of photographic recording equipment to measure radiant energy. With this procedure, many measurements of radiant energy can be recorded simultaneously and permanently.

The measurement of the responsivity of photographic media and of the relations between exposure and density of developed images.

Pertaining to the measurement of the intensity of light.

Photocells of various kinds used to measure photometric quantities; i.e., intensity, luminance and illuminance. Meter readings are used to express illuminance and, by calibration, to measure...

Photometry is the branch of science that deals with the measurement of light, particularly in terms of its intensity and the way the human eye perceives it. It involves the quantification of visible...

A camera equipped with angular scales in altitude and azimuth. The scale readings are imprinted on the film when an exposure is made. The exact point indicated by the scale readings is shown by...

Piezoresistance is a phenomenon in materials science and physics where the electrical resistance of a material changes in response to applied mechanical stress or strain. This change in resistance...

The measurement of the rotation of the plane of polarization of radiant energy, usually through the use of a polarimeter.

Positioning generally refers to the determination or identification of the location or placement of an object, person, or entity in a specific space or relative to a reference point. The term is used...

A prism is a geometric optical element with flat, polished surfaces that refract light. It is typically a solid, transparent object with at least two flat surfaces that are inclined relative to each...

Measurement of surface roughness or quality through the use of a diamond-pointed stylus connected to a coil in an electric field. As the stylus is traced across the surface, a current is created that...

The measurement of surface temperature by a thermograph that forms a pattern of the heat radiated by the surface on a luminescent screen.

A noncontact sensor used in the remote measurement of position, speed or other variables of moving parts.