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Bristol Instruments, Inc. - 872 Series High-Res 4/24 LB
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separate absorption and multiplication region avalanche photodiode
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.
separation filters
Three filters used in making a color print of a color negative, red, green and blue-violet, respectively. Each filter transmits about one-third of the visible spectrum onto the print.
sextant
A handheld navigational instrument used to measure the elevation angle of celestial bodies such as the sun. An image of the sun is viewed through a small telescope via two plane mirrors so that any...
shallow
A term used to denote a concave surface having too long a radius of curvature. That is, its negative power is too small or low.
sheet grating
A three-dimensional grating designed with thin metal sheets to remain opaque to all but one specific and predetermined wave.
shining -> clearing
Also called shining. Grinding and polishing one surface of a blank to permit a more thorough examination for quality.
shock wave
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...
short wavelength infrared
Short wavelength infrared (SWIR) refers to the portion of the infrared spectrum that encompasses wavelengths roughly between 1,000 and 3,000 nanometers (nm). In the electromagnetic spectrum, infrared...
short-arc lamp
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...
shutter speed tester
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...
sign conventions
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...
silica -> silicon dioxide
An abundant material found in the form of quartz and agate and as one of the major constituents of sand. The silicates of sodium, calcium, and other metals can be readily fused, and on cooling do not...
silicon carbide light-emitting diodes
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...
silicon dioxide
An abundant material found in the form of quartz and agate and as one of the major constituents of sand. The silicates of sodium, calcium, and other metals can be readily fused, and on cooling do not...
silver halide emulsion
An emulsion in which grains of the photosensitive material silver halide are deposited. Each grain, when exposed to light, either develops or fails to develop as a unit, leaving a dark or clear...
simultaneous location and mapping
Technology that uses data from an array of sensors, one of which is commonly lidar, to solve the problem of creating a map of an unknown environment while simultaneously maintaining a location within...
sine wave response -> modulation transfer function
Also called sine wave response and contrast transfer function. The modulation transfer function is the ratio of the modulation in the image to the modulation in the object as a function of frequency...
single molecule localization microscopy
Single molecule localization microscopy (SMLM) is a group of super-resolution microscopy techniques that surpass the diffraction limit of traditional optical microscopes, allowing for the...
single-mode waveguide (or fiber)
An optical waveguide in which only the lowest order bound mode, which may consist of a pair of orthogonally polarized fields, can propagate at the wavelength of interest.
single-photon avalanche diode
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...
single-photon emission computed tomography
A medical imaging method in which gamma camera heads rotate about the patient to detect radionuclides, enabling physicians to monitor functions within the body such as metabolism or blood flow.
sisyphus cooling
Sisyphus cooling is a technique used in atomic physics to achieve ultracold temperatures of atoms or molecules by exploiting the periodic motion of particles in optical traps or lattices. The name...
small-angle x-ray scattering
The investigation of microstructures by an instrument that generates a narrow, highly collimated beam of x-rays.
soft coating
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...
solar occultation
Measurement of absorption by the gas of interest in the 2- to 6-µm range as a function of tangent height pressure. The pressure profile may be inferred by using CO2 absorption profile...
solid-state laser
A solid-state laser is a type of laser that uses a solid gain medium (as opposed to a liquid or gas) to produce coherent light. The term "solid-state" refers to the fact that the active medium, where...
solid-state linear motor -> piezo worm
A piezoelectric translator that moves up and down a spindle like a caterpillar. It clamps itself at one end, expands, clamps the other end, releases the first end, and then contracts and begins the...
soliton
Any isolated wave that propagates without dispersion of energy. Specifically to photonics, an ultrashort pulse of laser light that propagates through a waveguide without characteristic chromatic...
sonde
A ruggedized scintillation counter used in oil well logging. The cylindrical housing contains a gamma ray source, a crystalline scintillator and a photomultiplier tube. As the sonde is drawn through...
space charge
A volumetric electrical charge resulting from a flow of charged particles across a gap.
speckle imaging
A technique for obtaining improved resolution of images produced by large telescopes and distorted by the effects of atmospheric turbulence. Many individual exposures are recorded at high speeds by a...
speckle interferometry -> speckle metrology
Refers to the variety of techniques that use the interference pattern produced by laser light diffusely reflected by an object. There are two basic techniques: direct laser photography, used when...
speckle metrology
Refers to the variety of techniques that use the interference pattern produced by laser light diffusely reflected by an object. There are two basic techniques: direct laser photography, used when...
spectral flow cytometry
Spectral flow cytometry is an advanced flow cytometry technique that expands the capabilities of traditional flow cytometry by utilizing spectral information from fluorochromes to enhance...
spectral signature
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...
spectrochemical equipment
Equipment used for chemical analysis by investigation of the spectra formed and observed in chemical activity. Of particular use are spectrographs for recording the emission spectra of substances...
spectrometer mask
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...
spectrophone technique
Gas detection measurement technique that uses a built-in capacitative microphone to calculate the amount of absorbed laser power in a gas cell according to variations of gas pressure.
spectroscopic light source
A discharge tube filled with various gases and used as a source in spectroscopy.
spectroscopy
Spectroscopy is a technique used in the study of interactions between matter and electromagnetic radiation. It involves measuring and analyzing how different materials absorb, emit, or scatter light,...
spicule
A feature in the chromosphere of the sun formed by a jet of gas that reaches from the chromosphere into the corona and has the appearance of a brightly luminous spike.
SPIN
Acronym for self-aligned polysilicon interconnect N-channel. A metal-gate process that uses aluminum for the metal-oxide semiconductor (MOS) gate electrode as well as for signal and power supply...
spiral scanning
A scanning process in which the greatest amount of radiation determines part of a spiral motion rotating in one direction.
spontaneous emission
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...
sputtering
A vacuum deposition method in which the coating material (target) is removed from the surface of the coating source (cathode) by ion bombardment and deposited upon the substrates.
sputtering equipment
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...
standard lens
A lens whose focal length is roughly equal to the diagonal of the negative format of the camera on which it is mounted.
standing wave
The combination of two waves having the same frequency and amplitude and traveling in opposite directions. Standing waves are indicated by a stationary set of nodes spaced one-half wavelength apart...
static beam shaping
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...
steady-state condition -> equilibrium mode distribution
The condition in a multimode optical waveguide in which the relative power distribution among the propagating modes is independent of length.

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