8,738 terms
Photonics Dictionary
Search 8,700+ definitions in the Photonics Dictionary—your authoritative source for terms in optics, lasers, imaging, fiber optics, and related technologies.
SQUIDsuperconducting quantum interference device
SQW-GRINSCHsingle-quantum-well, graded index separate confinement heterostructure
srsteradian
SRsynchrotron radiation
SRAMstatic random access memory
SRCscratch-resistant coating
SRDsuperradiant diode
SREMscanning reflection electron microscopy
SRFself-referenced fringe
SRSstimulated Raman scattering
SSsingle scattering
SSCsuperconducting supercollider
SSISsolid-state image sensor
SSLsolid-state laser
SSMstage scanning microscope
SSPDself-scanned photodiode array
Ststokes
ST-LCDsupertwist liquid crystal display
stabilized light sourceA light source that does not fluctuate despite temperature changes.
stabilizing platformA platform mount used to hold sensitive optical instruments immobile.
stable multipass Fabry-Perot interferometerA plane-parallel interferometer that yields extremely high contrast over a wide range of finesse values without significantly reducing transmission.
stable resonatorA laser resonator in which a mode oscillating between the mirrors will converge upon the laser's longitudinal axis.
stacked hologramThe superimposing of holographic pages in a thick, erasable storage material by changing the reference and object beams. This extends the capacity of holographic memories.
stacked optical memoryA 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...
stacked-diode laserA 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...
stadia scaleA reticle pattern in a surveying instrument consisting of parallel lines that can be superimposed on a calibrated rod, making possible determination of the distance from the instrument to the rod.
stadia surveying -> surveying instrumentsInstruments used for measuring angles and occasionally lengths on the ground. The principal surveying instruments are the level, the stadia telescope, the transit and the theodolite. Laser...
stadimetryThe 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.
stage micrometerIn microscopy, a calibrated scale on a slide that may be viewed to determine the exact magnification factor of the microscope.
standard lensA lens whose focal length is roughly equal to the diagonal of the negative format of the camera on which it is mounted.
standard refractionThe refraction that would take place in an idealized atmosphere where the refractive index is reduced uniformly with height at the rate of 39 x 10-6 per kilometer.
standard thermal profileIn 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...
standing waveThe 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...
star couplerA passive coupler that distributes signals from one or several inputs among a larger number of output waveguides arranged schematically as a star configuration.
star testingThe visual examination by a trained observer of the image of a point source. Any coloring or departure from the Airy disc rings indicates the presence of aberrations in the lens forming that image.
star topologyIn local area networking, arrangement of the satellite nodes around a central node through which all routing of network data takes place.
staring sensor array -> mosaic detector arrayA group of photosensors arranged in a grid-like pattern covering the entire field of view, enabling them to record it all at once (as a camera records an image on film) rather than by scanning parts...
Stark broadeningSpectrum broadening that results from the influence of an electric field.
Stark effectThe 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...
starting voltageIn a laser, the voltage necessary to initiate electrical discharge, somewhat higher than that needed to sustain it.
static beam alignmentThe degree to which a laser beam is aligned parallel to the housing axis.
static beam shapingA 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...
static electricity -> electrostatic chargeThe effect produced by electrical charges or fields alone, without interaction with magnetic influence.
static fatigueThe application of a constant stress to an optical fiber.
STCScience & Technology Center
stdstandard
steady-state condition -> equilibrium mode distributionThe condition in a multimode optical waveguide in which the relative power distribution among the propagating modes is independent of length.
stealthThat characteristic which makes a weapon system less visible to radar, optical, acousto-optic, infrared and other military sensors.
STED microscopySTED microscopy, or stimulated emission depletion microscopy, is a superresolution imaging technique in fluorescence microscopy that surpasses the diffraction limit, enabling the visualization of...
Stefan-Boltzmann lawThe formula that indicates the total radiation at all wavelengths from a perfect blackbody. W Total = 5.67 x 10-12 T 4(W/cm2)
Photonics Dictionary