403 terms
Photonics Dictionary: T
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ttorr
Ttransmission; tesla; tera-
t numberThe equivalent f number of a fictitious lens that has a circular opening and 100 percent transmittance, which would give the same central illumination as the lens being considered:
where...
T stop -> t numberThe equivalent f number of a fictitious lens that has a circular opening and 100 percent transmittance, which would give the same central illumination as the lens being considered:
where...
t-numbertransmission number
T/Rtransmit/receive unit
TABtape automated bonding
tableSee honeycomb table; indexing table.
tachometerAn instrument designed to measure the rate of rotation of components, such as shafts.
TAITemps Atomique International
talbotOne lumen-second, the SI unit of the quantity of light.
Talbot's bandsThe series of interference bands that appear in the spectrum when a specified glass plate is inserted into a spectroscope, from the side of the blue portion of the spectrum, so that the plate...
Talbot's lawThe law stating that the brightness of an object that is examined through a slotted disc, rotating over a critical frequency, is proportional to the angular aperture divided by the opaque sectors.
tantangent of
tangent ogiveIn optics, a shape often given to the leading edge of a projectile. In any side view it appears as a pointed arc, while any cross section perpendicular to its long axis appears as a circle.
tangential distortionOptical aberration such that image magnification varies with ray distance from the optical axis in a radial distortion.
tanhhyperbolic tangent
TAPtarget angular position
tapA device for extracting a portion of the optical signal from a fiber.
tapered transmission line -> tapered waveguideA waveguide having a characteristic that is altered continuously with the distance traveled, relative to the axis of its path.
tapered undulator -> undulator magnetA device used in a free-electron laser to convert the electron-beam's energy into microwave laser radiation by creating a magnetic field of alternating polarity through which the free electrons are...
tapered waveguideA waveguide having a characteristic that is altered continuously with the distance traveled, relative to the axis of its path.
target1. The anode or anticathode of an x-ray tube that emits x-rays when bombarded by electrons. 2. The screen in a television imaging tube that is scanned by an electron beam to determine the...
target angular positionMeasurement estimated from the position of the image's centroid.
target size and orientationAngular tracking measurement estimated from the properly normalized image second-moment tensor.
TAStarget acquisition system
TASRtunable, all-optical signal regenerator
Taylor criterionStates that in interferometers in which the separation of the maxima is equal to the half-value width, a slight drop in intensity between fringes is distinguishable and the fringes can be considered...
Tb/sterabits per second
TCLthrough-camera-lens
TCRtemperature coefficient of resistance
TDAStracking and data acquisition system
TDDMtime division demultiplex
TDItachometry displacement integration; time delay integration
TDLtunable diode laser
TDMtime division multiplexing
TDRtime-domain reflectometer
TDRStracking and data relay satellite
TDStime-domain spectroscopy
TEthermoelectric; transverse electric
TEAtransversely excited atmosphere
TEA laser -> transversely excited atmosphere laserAlso known as TEA laser. A coherent optical source with a wide wavelength range in the infrared, visible and ultraviolet that uses an electrical discharge transverse to (across) the optical axis to...
tearingIn television, a lateral displacement of the lines from their normal position due to the instability of a synchronizing circuit. Visually, it appears as though parts of the images had been torn away.
technicolorThe color process that is used to form positive color cine films by dye transfer or imbibition, based on the use of separate matrices that superimpose yellow, magenta and cyan dye images on the final...
tee couplerA passive coupler that connects three ports.
TELDtransferred electron device
telecentric lensThere are three types of telecentric lenses:
-Image-space telecentric lenses are those in which the aperture stop is located at the front focus, resulting in the chief rays being parallel to the...
telemeter1. The term used to describe any of the many instruments used to remotely record physical dimensions, such as strain, temperature or pressure, and transmit this data to a receiving station. 2. A...
telemetryThe science of sensing and measuring information at some remote location and transmitting the data to a convenient location for reading or recording.
teleobjective -> telephoto lensA compound lens so constructed that its overall length is equal to or less than its effective focal length.
Photonics DictionaryT