8,616 terms
Photonics Dictionary
RSPMrandom spatial phase modulator
RSRERoyal Signals and Radar Establishment
rssroot sum square
RSSray surfaces per second; reduced space symbology
RTreal time; remote terminal; room temperature
RTEradiative transfer equation
RTGradioactive thermoelectric generator
RTSreal-time system
RTSP protocolRTSP, or real-time streaming protocol, is a network control protocol designed for controlling streaming media servers. It is used for establishing and controlling media sessions between endpoints....
rubA type of scratch.
ruby laserThe optically pumped, solid-state laser that uses sapphire as the host lattice and chromium as the active ion. The emission takes place in the red portion of the spectrum.
rugateBearing alternate ridges and grooves; corrugated. Said of some optical surfaces.
Rugate filtersA Rugate filter is a type of optical filter that is designed to have a continuously varying refractive index profile throughout its thickness, rather than the discrete layers found in traditional...
run end codingA digital imaging method whereby the first gray level in the ordered sequence and the position of the first lengths of all runs are specified; used when there are only two possible gray levels...
run length codingA digital imaging method whereby the first gray level of each sequential point-by-point sample and its position in the succession of gray levels is encoded. It is used when there is a tendency for...
runner cutA term describing a type of scratch.
runoutIn a linear stage, any deviation from the desired translation across a flat, straight line.
RuticonA ruticon is an opto-electronic device in which light going through it can be modulated by an electric field.
The intensity distribution of the resulting image can be precisely controlled....
RVIremote visual inspection
Rydberg atomThe term "Rydberg atom" refers to an atom in a highly excited state where one or more of its electrons are in a Rydberg orbital. A Rydberg atom is characterized by having an electron orbit that is...
RZreturn to zero
Ssiemens
ssecond
S-ARROWsimplified antiresonant reflecting optical waveguide
S-SEEDsymmetric self-electro-optic effect device
S/LJsemiconductor/liquid junction
S/Nsignal-to-noise ratio
Sabattier effectThe reversal of a developed image due to the exposure of the partially developed image to actinic light.
saccadic motionThe 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.
saccharimeterA special-purpose polarimeter having a scale calibrated directly in the concentration of sugar in the test solution.
SADselected area diffraction
saddleA term used to describe a saddle-shaped -- i.e., convex along one axis, concave along the other -- polished surface, generally an error, whose contours are apparent by the shape of Newton's rings.
safelightFiltered light to which photographic or other photosensitive materials are not responsive; used to illuminate darkrooms when film is being processed. The color of the filter varies according to the...
sag1. In the geometric sense, an abbreviation for the term "sagitta,'' the height of a curve measured from the chord.
and it is exact for a parabola. 2. Conforming a sheet of glass to a...
sagsagitta
sagged bevelThe shape of the edge of a concave surface when the depth of the bevel plane to the vertex of the surface is controlled to a required distance.
sagitta -> sag1. In the geometric sense, an abbreviation for the term "sagitta,'' the height of a curve measured from the chord.
and it is exact for a parabola. 2. Conforming a sheet of glass to a...
Sagnac interferometerSagnac interferometry is a technique used to measure rotation or angular velocity based on the principle of interference. It relies on the Sagnac effect, named after the French physicist Georges...
Saha equationFormula that describes the thermal equilibrium of gas electrons and ions as a direct function of variations in temperature.
SALIsurface analysis by laser ionization
SAMscanning acoustic microscope; scanning Auger microscopy
SAM-APDseparate absorption and multiplication region avalanche photodiode
SAMAScientific Apparatus Makers' Association
SAMPESociety for the Advancement of Material and Process Engineering
sample pointOn a chromaticity diagram, the point that denotes the chromaticity sample.
sample-and-hold circuitA device that acquires a signal and then stores it for a specified period of time before processing, and used, for example, to reduce noise as in correlated double sampling.
sampling theorem -> Nyquist criterionIn image acquisition (and sampling theory), the postulate that the pickup sampling frequency must be a minimum of twice as high as the Nyquist rate of brightness change of any detail to be resolved....
SANstyrene acrylonitrile; storage area network
sand holeA crude area on the polished surface, produced during coarse grinding, that subsequent fine grinding does not remove, owing, to some extent, to coarse grains of grinding sand that mixed with finer...
sandwich holographyThe simultaneous exposure of two holographic plates with emulsions facing the object. After deformation, a second pair of plates is exposed to the deformed object. The back plate of the initial pair...
Photonics Dictionary