Photonics Dictionary: P

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...

Having coincident focal points.

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

A phase screen, in the context of optics and wave optics, refers to a surface or medium that introduces a phase delay to an incident wavefront passing through it. This concept is often used in the...

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

A process used in pyrometry and photothermometry to create a photographic record of a surface's temperature gradients. Essentially, it involves the exposure of a glowing phosphorescent surface to the...

Periodic interruptions of a light beam incident on an absorbing medium that produce heat, expansion and acoustic wave generation. Since the amplitude of this wave is proportional to the absorbed...

The responsivity of a photocathode to luminous energy equal to the ratio of the photoelectric emission to the incident luminous flux.

Photocathodes are specialized materials or surfaces that exhibit the photoelectric effect, wherein the absorption of photons leads to the emission of electrons. When photons with sufficient energy...

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...

A photodiode detector is a semiconductor device that converts light into an electrical current. It operates based on the principle of the photoelectric effect, where photons of light incident on the...

Photodynamic inactivation (PDI) is a therapeutic approach that utilizes the combination of light, a photosensitizer, and molecular oxygen to induce cell death or inactivate microorganisms. This...

The transformation of incident radiant energy into a photoelectric emission current.

The control of an instrument or electrical circuit by the current produced by varying radiation incident to a photoelectric cell.

An instrument that uses a photocell to detect and measure the intensity of incident light.

A relay that opens or closes an electrical circuit depending on the intensity of the light incident to a photoelectric device contained in the relay.

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

A particular type of phototube having increased sensitivity as a result of the glow initiated by light incident to the cathode.

A photomultiplier tube (PMT) is a highly sensitive vacuum tube that detects and amplifies low levels of light. It is widely used in various applications where high sensitivity, fast response times,...

An infrared detector in which radiation passes through a doped germanium crystal, creating a voltage drop that can be measured in terms of incident intensity.

The induction of an electric field in a semiconductor by an incident laser beam. The technique has rapid response time at room temperature.

An instrument in which visible light beyond the critical angle from a metallurgical microscope is focused on a reference surface. A certain fraction of the incident light tunnels through air to the...

The property exhibited by a substance having electrical conductivity that decreases as the intensity of the incident visible radiant energy increases.

The surface from which electrons are ejected by the incidence and absorption of photons.

A solid-state device that acts as a high-speed power switch, and that is activated by incident radiation.

The cause of some forms of laser injury in which tissue absorbs incident laser light and experiences a damaging rise in temperature. The severity of the damage is dependent on the rate of energy...

A phototransistor is a type of semiconductor device that converts light energy into electrical signals. Similar to a regular transistor, it consists of a semiconductor material (such as silicon) with...

The generation of a difference in electric potential between two electrodes when radiation is incident on one of them.

A PIN photodiode is a type of photodetector or semiconductor device used to convert light signals into electrical signals. The name "PIN" is derived from the arrangement of the three semiconductor...

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,...

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

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...

Polymers are large molecules composed of repeating structural units called monomers. These monomers are chemically bonded together to form long chains or networks, creating a macromolecular...

The polymerase chain reaction (PCR) is a widely used molecular biology technique used to amplify a specific segment of DNA (deoxyribonucleic acid) through a series of temperature-controlled cycles....

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...

The removal of a sharp edge on an optical element by grinding, to prevent accidental chipping of that edge during subsequent handling.

Separation of incident laser pulses by several seconds so holographic plates can be changed and sandwiched between the pulses. This technique combines the short exposure time of pulsed holography...