Photonics Dictionary: S

An imaging system that uses a mosaic of tiny light-sensitive semiconductors (phototransistors) to produce individual outputs that are then converted into a coherent video signal.

A combination of components arranged so as to perform at least one function.

Abbreviated SoC. A single chip containing all the electronic circuits required for a complete, working product. SoCs are similar to microcontroller technology but provide additional components. A SoC...

The movement of the eye as it focuses on details of a scene. Some imaging systems mimic this movement by small, rapid scanning motions of the sensor.

Formula that describes the thermal equilibrium of gas electrons and ions as a direct function of variations in temperature.

Sapphire optical fiber is a type of optical fiber made from single-crystal sapphire, which is a form of aluminum oxide (Al2O3) that is highly transparent in the infrared region of the electromagnetic...

A sapphire window refers to a transparent optical component made from sapphire crystal. Sapphire is a single-crystal form of aluminum oxide (Al2O3) that is highly prized for its exceptional optical...

Sapphire refers to a crystalline form of aluminum oxide (Al2O3) that is used in various optical and photonic applications due to its exceptional optical, mechanical, and thermal properties. Sapphire...

A device composed of a light source and phototube used to scan a moving strip of material in photoelectric side-register control systems.

An optical system that records inhomogeneities within a medium by detecting the energy refracted by that portion of the medium in which the inhomogeneity occurs. The image appears in the form of a...

A scientific CMOS (complementary metal-oxide-semiconductor) camera is a type of digital camera specifically designed for scientific imaging applications. It employs CMOS sensor technology, which...

A scintillation crystal, also known simply as a scintillator, is a material that emits light when it interacts with ionizing radiation such as gamma rays, x-rays, or charged particles. The emitted...

A self-interference effect that generates random patterns; secondary speckle pattern (SSP) typically occurs in diffuse reflections of a laser on paper, white paint or rough surfaces. By tracking both...

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

Seidel aberrations refer to a set of monochromatic aberrations in optical systems, named after the German mathematician and physicist Ludwig von Seidel. These aberrations describe deviations from...

Self-phase modulation (SPM) is a nonlinear optical phenomenon that occurs when an intense laser beam passes through a medium, causing a change in the phase of the light due to its interaction with...

A semiconductor is a type of material that has electrical conductivity between that of a conductor and an insulator. In other words, semiconductors have properties that are intermediate between...

1. A generic term for detector. 2. A complete optical/mechanical/electronic system that contains some form of radiation detector.

A closed-loop system that is constantly adjusted in response to input signals generated within the system.

The Shack-Hartmann wavefront sensor is an optical device used for measuring the wavefront aberrations of an optical system. It is widely used in adaptive optics systems to correct distortions and...

1. The sorting of lenses by their color. 2. In an optical system, an irradiance or brightness gradient in the image that is not present at the object.

Interruption in the normal flow of a plasma or fluid characterized by sharp rises in velocity, temperature and pressure. As the shock passes into a gaseous compound, gas particles are heated and...

Systeme Internationale d'Unites, the international metric system of units.

Frequently used in astronomical measurement, it is based on the diurnal rotation of a star relative to the fixed stellar system.

A convention that defines specific dimensions of an optical system, such as the image distance or radius of curvature of a lens or mirror, as negative or positive to facilitate calculations based on...

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...

An instrument that uses a blackened silver-disc reflector with a shutter to create temperature fluctuations that are proportional to the intensity of the solar radiation incident upon it. Using the...

A fiber optic transmission system in which data can go in only a single direction.

A passive infrared system that uses two line-of-sight telescopes to generate both narrow and wide field-of-view images of the same target area, which can be presented on a single split screen or on...

An object that has a sinusoidal variation of luminance. Its image will have a sinusoidal variation of illuminance and the only effect of degeneration by the lens system will be to reduce the...

In a dual-ring local area network, a node that is connected only to the primary, active ring and not to the secondary ring that provides a backup in case of cable or system failure.

An advanced technique that allows the detection of one molecule within a crystal or a cell through optical excitation. Single-molecule spectroscopy (SMS) can image at subwavelength scales, down to a...

A single-photon avalanche diode (SPAD) is a specialized type of photodetector designed to detect extremely weak optical signals, down to the level of single photons. SPADs are widely used in...

The angle at which photoelectric sensors are aligned to prevent light from being reflected back to the sensor from the object during retroreflective sensing; also, the angle a measured part is...

Any ray through an optical system that is not a meridional ray. The plane created by a refracted skew ray does not contain the optical axis.

A system employing a dark trace tube in which the opacity of the screen is varied as a function of the power of the beam.

Variations in signal detected on a bolometer that are caused by instabilities in the temperature of the sky.

A crystal, glass, or quartz slicing and cutting machine is a specialized piece of equipment used in the manufacturing process to precisely cut and slice materials such as crystals, glass, and quartz...