Photonics Dictionary: S

A waveguide with a rectangular cross section that is composed entirely of dielectric materials.

Characteristic of the relationship between photoelectric activity and the wavelength of incident radiation.

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...

Scalar diffraction theory is a simplified approach used to describe the propagation of electromagnetic waves, particularly light, as they encounter obstacles or apertures. It is termed "scalar"...

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

A high-resolution imaging instrument that can detect and measure the positions of individual atoms on the surface of a material. A very fine conductive probe is placed at a distance of 10 to 20...

Scientific complementary metal-oxide semiconductor (sCMOS) refers to a type of image sensor technology specifically designed for scientific and industrial imaging applications. Unlike traditional...

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 scintillation detector is a radiation detection device that utilizes scintillation crystals to detect and measure ionizing radiation, such as gamma rays, x-rays, or charged particles. It consists...

Second-order nonlinear optical properties refer to a class of phenomena exhibited by certain materials in response to intense light, typically in the realm of optics and photonics. Nonlinear optical...

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

A photoconductive cell consisting of a layer of selenium on a substrate whose electrical resistance varies with the illumination falling on the cell. Selenium cells have been replaced largely by...

Any material that derives its energy from chemically or electrically induced reactions; isotope or radium excitation is used to form the glow in luminescent watch or clock hands.

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...

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

A surface-mount device (SMD) is an electronic component that is mounted directly onto the surface of a printed circuit board (PCB) rather than being inserted into holes drilled in the board (as with...

A compact high-pressure light source in which an electrical discharge between electrodes spaced no more than 12 mm apart occurs in a xenon or other gas medium, providing a visible light resembling a...

A device used to measure the opening time of a shutter. The most common devices depend on the charging or discharging of an electrical condenser, or on the production of a curve of open area against...

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

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 solid-state device, composed of silicon, that is used to convert radiation into electrical energy.

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 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...

An array of active optical devices (modulators, laser diodes and/or detectors), each of whose electrical inputs or outputs are directly connected to electronic logic circuits, which also are a part...

An electric discharge lamp in which the conducting vapor is that of metallic sodium instead of the usual mercury. It emits a strong yellow light of a single wavelength.

A group of solar cells that are electrically contacted and physically arranged so that they may be oriented in the direction of the sun simultaneously.

A series of solar cells arranged to collect solar radiation and to generate a given amount of electrical energy.

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.

The ratio of emitted optical power of a source to the input electrical power.

A volumetric electrical charge resulting from a flow of charged particles across a gap.

A spatial light modulator (SLM) is an optical device that modulates or manipulates the amplitude, phase, or polarization of light in two dimensions, typically in the form of an array. SLMs are...

An automatic scanning instrument that is used to study a substance's fluorescence over a wide range of wavelengths. It consists of a radiation source, a grating that functions as the monochromator in...

Sputtering equipment is machinery used in the process of physical vapor deposition (PVD), specifically sputtering. Sputtering is a method of depositing thin films of material onto a substrate surface...

A sputtering target is a solid material used in the process of physical vapor deposition (PVD), specifically sputtering. Sputtering targets are typically made of metals, metal alloys, or compounds...

Spectrum broadening that results from the influence of an electric field.

The splitting or shifting of spectral lines or energy levels caused by the application of a strong transverse electrical field. It often is studied with a canal-ray tube that has a third electrode...

In a laser, the voltage necessary to initiate electrical discharge, somewhat higher than that needed to sustain it.

A cathode-ray tube combined with an electrostatic storage unit that is used to introduce, store and retrieve information translated into electric charge form.

A device that produces brief flashes of light for observing the behavior of an object during a short interval. One of the most effective means for accomplishing this is a gaseous tube energized by...

Controlled beam technology that introduces beams of sunlight through holes in a roof that are relayed throughout the building by a series of mirrors and lenses. Ideally, cool lighting is obtained by...