Photonics Dictionary

The force that stimulates the emission of an electrical current when photovoltaic action creates a potential difference between two points.

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

An electron tube having a photocathode for the emission of a photoelectric current.

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...

Photovoltaic (PV) refers to a technology that converts sunlight directly into electricity using semiconductors. The term "photovoltaic" is derived from the words "photo," meaning light, and...

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...

Introduced into the laser beam from localized fluctuations in current density within the plasma itself. These fluctuations represent macroscopic changes of gain in the laser.

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...

Refers to the voltage and current necessary for the operation of circuit devices.

A step before fusion splicing that involves cleaning the fiber end with low-current electricity.

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...

A device designed to detect frequency-modulated signals by forming a unidirectional pulse from each sine wave. The direct current of the pulse is proportional to the frequency of the...

A series of capacitors and inductors connected to the flashlamp in a pumped Nd:YAG laser system in order to regulate the pulse shape of the current delivered to the lamp at a given operating voltage.

Unlike the thermocouple or bolometer, the pyroelectric infrared detector is a current source with an output proportional to the rate of change of its temperature. Capable of extremely rapid response...

A current-source thermal detector used to detect and study the pulses obtained from particular lasers.

Quantum efficiency (QE) is a measure of the effectiveness with which a device or system, typically in the context of photonics or electronics, converts incoming photons (light) into a useful output...

Noise generated within an optical communications system link that has both internal (dark current) and external (background noise, or noise in signal) components.

Operation in which the minimum detectable signal is set because of variations in the average signal current; e.g., quantum noise.

A very uncommon lamp in which a tungsten electrode is heated to incandescence by a radio-frequency electrical current.

The inherent laser amplitude noise relative to the average optical power produced by the laser; the RIN decreases rapidly as current is increased.

Remote sensing is a method of data collection and observation where information about objects, areas, or phenomena on Earth's surface is gathered from a distance, typically using sensors onboard...

A crucible made of electrically resistive material through which a current is passed to heat the material inside, which then evaporates and is deposited as a thin film on a substrate. Resistance...

A device having electrical resistance and used in an electric current for purposes of protection, operation or control of current.

The gain that occurs between light intensity incident on a CCD given by the photocurrent produced.

Voltage that produces current flow in the direction of greater resistance to the steady-state direct current; i.e., from the cathode to the anode.

Measurement of the time elapsed during the current output change from 10 to 90 percent in a photoconductor.

Conductor element for use in integrated electro-optic systems that measures current flowing through it.

Characteristic of dissimilar metals in thermoelectric solar cells whereby separate junctions exhibiting distinct temperatures transform incident voltage into a current.

A photocathode that receives radiation from one side and emits a photoelectric current from the opposite side.

An avalanche photodiode in which the light-absorbing area is a low-bandgap material and the PN junction is placed in an area of high-bandgap material, reducing dark current and increasing gain.

The electric conductance of a conductor in which a current of 1 ampere is produced by an electric potential difference of 1 volt.

Noise generated in the flow of current in the photomultiplier, produced by the intentional or controlled application of optical power to the photocathode.

Silicon carbide (SiC) light-emitting diodes (LEDs) are semiconductor devices that emit light when an electric current is applied to them. These LEDs are made using silicon carbide as the...

A silicon photodiode is a semiconductor device that converts light into an electrical current. It is a type of photodetector specifically designed for detecting and measuring light intensity. Silicon...

The ability of an electrical current to destroy superconductivity by means of the magnetic field generated by the current. The temperature of the material is not raised, and the effect is identical...

A device for converting sunlight into electrical energy, consisting of a sandwich of P-type and N-type semiconducting wafers. A photon with sufficient energy striking the cell can dislodge an...

In micropositioning, a remote positioning device in which an electric current drives a movable armature mounted on an electromagnetic coil.

A type of laser used when a great amount of power is required. Avoiding the bulk of large numbers of optical lenses, this instrument offers high-output intensity and a small emitting region at...

Interval between cutting off a photoconductor's signal and the fall of current output to 90 percent.

In a laser, the voltage necessary to sustain a constant operating current, somewhat less than that needed for start-up.

A refrigeration method based on the Peltier effect. When an electric current passes through a thermocouple of two dissimilar metals joined in two places, heat is absorbed at the cold junction and...

Thermophotovoltaic (TPV) refers to a technology that converts heat energy into electricity using the principles of thermophotovoltaics. In a thermophotovoltaic system, thermal radiation from a heat...

1. Voltage at which a PN junction begins to pass a current. 2. In a solid-state lamp, the voltage at which light is first emitted.