Photonics Dictionary: T

Protective material surrounding the cladding of an optical fiber that allows the fiber no play within it.

Multiple exposures of holograms, one for each position of a vibrating image, that are used for vibration analysis and that yield a record of the time-averaged irradiance distribution at the hologram...

Effect whereby two electrons lose synchronism with the accelerating field and are lost during synchronous radiation. The effect is produced by the scattering of the electrons that are oscillating in...

A process used to control thickness and parallelism precisely during the production of plane-parallel plates. Elements are cemented to a blocking tool and their upper surfaces are polished. A second...

The complex function, H(f), equal to the ratio of the output to input of the device as a function of frequency. The amplitude and phase responses are, respectively, the magnitude of H(f) and the...

A single long gate electrode that transfers the line of charge packets to the transport shift register in a charge-coupled device.

The rate at which data can be read from a CD-ROM.

The method used to measure the index profile of an optical fiber by placing it in an interferometer and illuminating the fiber transversely to its axis.

Twisted intramolecular charge transfer (TICT) is a phenomenon observed in certain organic molecules containing electron-donor and electron-acceptor groups that are linked together within the same...

A testing device that provides a contour map of the emergent wavefront for the observer in terms of the given wavelength of the light.

The effect by which sufficiently small particles will scatter blue light at right angles to the incident beam. This scattered light is completely linearly polarized.

The 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...

States 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...

The 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...

A compound lens so constructed that its overall length is equal to or less than its effective focal length.

The ratio between the focal length of a lens having a longer focal length than that of the standard lens used with a camera, and the focal length of the standard lens. It is used to provide an...

A telescope lens is a primary optical component of a telescope system that gathers and focuses light to form an image. It is typically a curved, transparent piece of glass or other optical material...

A coating having pigments that change color when exposed to heat. This effect has been widely used to monitor hot spots in mechanical parts.

A characteristic of laser output, calculated by dividing the speed of light by the linewidth of the laser beam. The temporal coherence length of different lasers thus varies from a few centimeters to...

A technique used to suppress extreme noise amplification during digital image reconstruction that relies on smoothing and differentiation of the data by simplified least squared procedures.

Terahertz (THz) refers to a unit of frequency in the electromagnetic spectrum, denoting waves with frequencies between 0.1 and 10 terahertz. One terahertz is equivalent to one trillion hertz, or...

An optical matrix that does not require perfection in both states of the crosspoint, so that all the optical switches can be tap-off devices in which a fraction of the optical energy is transferred...

Refers to a notation system using a base of 3 and the numerical characters 0, 1 and 2.

A transparent block shaped accurately to reverse curvatures of the components it is used to test. By contacting an accurately finished negative lens shape with a newly made positive, the conformity...

The effect that characterizes an intense laser beam that is passed through an absorbing medium, causing the absorbed energy to produce density changes that can alter the intensity distribution of the...

The process of producing a visible two-dimensional image of a scene that is dependent on differences in thermal or infrared radiation from the scene reaching the aperture of the imaging device.

A thermal-infrared camera, often referred to simply as a thermal camera, is a type of imaging device that detects infrared radiation emitted by objects due to their temperature. Unlike traditional...

Thermal interface materials (TIMs) are substances or compounds used to enhance the thermal conductivity between two surfaces in contact. These materials are primarily employed in electronic devices,...

A term referring to various processes for forming visible images outside of a camera to be photographed on ordinary film. Unlike regular infrared photography, thermal photography is an indirect...

A refrigeration method based on the Peltier effect. When an electric current passes through a thermocouple of two dissimilar metals joined in two places, heat is absorbed at the cold junction and...

Also known as analog thermogram. The resultant photograph, illustrating, in tones ranging from black to white, the spatial relationship of the infrared radiation temperatures of the different details...

Thermography is a technique that involves the use of an infrared imaging device, called a thermal camera or infrared camera, to detect and visualize the infrared radiation emitted by objects. This...

The production of an image on a magnetic film that is exposed to infrared radiation and heated to a point above Curie temperature in regions of the image. The image is contacted with paramagnetic...

Thermophotovoltaic (TPV) refers to a technology that converts heat energy into electricity using the principles of thermophotovoltaics. In a thermophotovoltaic system, thermal radiation from a heat...

A type of recording material, usually a photodielectric polymer, offering in situ development mechanisms because of its density storage capabilities, high diffraction efficiencies and excellent noise...

Thin-film coatings are layers of material applied to the surface of an object or substrate, typically to modify its optical, electrical, or mechanical properties. These coatings are composed of thin...

Thin-film deposition equipment refers to machinery and tools used in the process of depositing thin layers of material onto a substrate surface. This technique is commonly employed in various...

Referring to compound semiconductor materials combining one element that has three valence electrons with one or more that have five. Examples include gallium arsenide and indium antimonide. (III-V).

A laser having a material, such as ruby, that has an energy state structure of three levels: the ground state (1) wherein excitation applied to the material raises ions in the material into the...

Three-photon microscopy is an advanced imaging technique that belongs to the family of multi-photon microscopy methods. It is used in biological and medical research to capture high-resolution images...

In visual perception, the smallest difference in illumination perceived on the average.

In laser damage testing, the exposure of many sites of a sample to different intensities of laser irradiation to discover the point at which the laser induces failure of the material.