Photonics Dictionary: S

A television system that uses a slow rate of horizontal scanning to increase its reproduction and transmittance accuracy of printed matter, photographs and illustrations.

A bomb guided to its target by some form of electro-optical system.

A term describing an antireflection coating that may be applied to optics that cannot tolerate the high temperatures usually required for normal "hard'' coatings. Such coatings lack durability...

An optical system that is designed to produce a high temperature in a specified area by the optical direction and concentration of solar radiation on that area. The system usually consists of a...

A solar simulator is a device used to replicate the spectrum and intensity of sunlight in a controlled environment for testing and research purposes. Solar simulators are employed in various...

1. The reduction in the developable density of a photographic emulsion that has been extremely overexposed. 2. In a laser system, damage resulting from ultraviolet radiation that degrades the lasing...

A beam instability, induced by index of refraction inhomogeneities and component damage of dirt and dust particles, that exhibits exponential growth and causes both system degradation and energy loss...

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...

Spatial resolution refers to the level of detail or granularity in an image or a spatial dataset. It is a measure of the smallest discernible or resolvable features in the spatial domain, typically...

In laser systems, the granular effect that is noted when observing the expanded cross section of a laser beam.

A power intensity pattern produced by the mutual interference of partially coherent beams that are subject to minute temporal and spatial fluctuations.

With respect to color photography, the measurement, at a given wavelength, of the way the color film modulates the radiant flux in the optical system containing the film.

Spectral repeatability refers to the consistency and reproducibility of spectral measurements across multiple trials or instances. It is a measure of how well a measurement instrument or system can...

A spectral signature, in the context of remote sensing and spectroscopy, refers to the unique pattern or characteristic spectral response of a material or object across different wavelengths of the...

A high-contrast transparency of the gas sought, or an array of exit slits that correlates with some features of the spectrum. No standardized formula for positioning, number or thickness has been...

A spheric lens, also known as a spherical lens, is a type of optical lens with at least one surface that is part of a sphere. This means that the lens surface is curved in a symmetrical manner,...

Spherical aberration is an optical aberration that occurs when light rays passing through a lens or curved optical surface do not converge or diverge to a single focal point. Instead of focusing to a...

Reciprocal magnetic interaction between nuclei in a molecular system facilitated by the binding electrons of the molecule.

A device through which scintillations are observed or counted through a magnifying lens system.

A cooling system used to attain and maintain desired low temperatures in infrared systems. The Stirling type is a mechanical refrigeration system capable of temperatures from 10 to 77 K.

A mask-alignment microscope used to produce and inspect microcircuits in the electronics industry. It provides flat-field, distortion-free images at all magnifications with a high-intensity vertical...

Radiation emitted when a quantum mechanical system drops spontaneously from an excited level to a lower level. This radiation is emitted according to the laws of probability without regard to the...

The distribution of energy about the image of a point source in the focal plane of an optical system.

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 light source that does not fluctuate despite temperature changes.

A memory system composed of a stack of holographic plates, a mode-locked laser and a rapid detector array. Ultrashort laser pulses are used to extract information from the stack. In this way, storage...

The determination of distance based upon the known size of an object and the size of its image at the image plane of an optical system.

In infrared imaging systems used for mass screening of printed circuit boards or other quality control applications, an image of an ideal component that is stored in the system's memory and then...

A technique for creating optimal performance in a system by producing a specific beam irradiance distribution, usually through the use of geometric optics. A common design involves the use of ray...

That characteristic which makes a weapon system less visible to radar, optical, acousto-optic, infrared and other military sensors.

STED microscopy, or stimulated emission depletion microscopy, is a superresolution imaging technique in fluorescence microscopy that surpasses the diffraction limit, enabling the visualization of...

The projection of the image beam by a cathode-ray tube through a mask, where it is deflected through the suitable character position in the mask and then deflected by another system to its suitable...

A television system in which the images produced appear three-dimensional.

In Stimulated Brillouin Scattering (SBS), an incident photon (usually laser light) interacts with acoustic phonons in a medium. The energy and momentum of the incident photon are transferred to the...

An engine in which work is performed by the expansion of a gas at high temperature; heat for the expansion is supplied through the wall of the piston cylinder.

The ratio of the illuminance at the peak of the diffraction pattern of an aberrated point image to that at the peak of an aberration-free image as formed by the same optical system.

A pulsed interferometer that permits the continuous quantitative mapping of the surface deformation of an adaptive optical element (e.g., a deformable mirror) and provides the capability for...

The pattern formed by a character generation cathode-ray tube system, in which the characters are composed of a sequence of line segments (strokes) generated by the electron beam motion with time...

Heat loss determined by the sum of rising and falling slopes at a constant temperature.

Correction of an optical system at four separate wavelengths. This correction, longitudinal and lateral, is possible with the help of three selected special glasses.

A metal, alloy or compound that loses its electrical resistance at temperatures below a certain transition temperature referred to as Tc. High-temperature superconductors occur near 130 K, while...

Supercontinuum refers to a broad spectrum of light that spans a wide range of wavelengths, typically from the visible to the near-infrared or even mid-infrared regions of the electromagnetic...

Superresolution refers to the enhancement or improvement of the spatial resolution beyond the conventional limits imposed by the diffraction of light. In the context of imaging, it is a set of...