Photonics Dictionary

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...

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...

A material used in the jacket of fiber optic cables.

A lens with an axial thickness adequate to make it producible.

A solar cell that is lightweight and flexible because of its construction by vacuum deposition of a semiconductor material (e.g., gallium arsenide or cadmium sulfide) onto a thin metal or plastic...

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

A method of scanning in which a frame transfer device produces a continuous video image of a moving object by means of a stack of linear arrays aligned with and synchronized to the movement of the...

The time domain is a concept used in signal processing and analysis to describe signals in terms of their behavior over time. In the time domain, signals are represented as functions of time, showing...

The elongation of a transmitted data pulse through a fiber optic due to the chromatic dispersion of the fiber material.

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...

Although low in sensitivity (approximately 10-7 m for helium-neon lasers), this holographic technique permits quantitative assessment of entire vibratory patterns of given structures in a single...

Time-correlated single photon counting (TCSPC) is a technique used in photon counting applications, particularly in the field of experimental physics, biophysics, and fluorescence lifetime imaging...

A laser fitted with up to eight optical fibers that transmit the energy to different workstations in turn.

Tip-enhanced Raman scattering (TERS) is a powerful technique that combines Raman spectroscopy with the enhanced spatial resolution provided by a sharp metallic or dielectric tip. TERS allows...

A Ti:sapphire laser is a type of solid-state laser that utilizes a titanium-doped sapphire crystal as the gain medium. The name Ti:sapphire comes from the combination of titanium (Ti) as the dopant...

In fiber optics, the annular region between two concentric circles; used to specify fiber cladding and core sizes.

A variation of tomography in which several photographs of a patient are taken at different angles, and back-projection of the resulting radiographs produces light distribution in a chosen...

The distribution of gray-scale values in an image.

Topological photonics is a branch of physics and optics that explores the application of topological concepts to the behavior of light in photonic systems. Drawing inspiration from the field of...

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...

In a cathode-ray tube, the visible line or lines formed on the screen by the deflection of the electron stream.

In polarized light, the plane of vibration that a polarizer will transmit.

In fiber optic communications, a light source whose beam can be modulated and sent along an optical fiber, and the electronics that support it.

Imaging materials that generally consist of a polyester base, a transparent electrically conductive layer and an organic photoconductive top coating. When charged and exposed to light, an...

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.

In the context of optics and lasers, a transverse mode refers to a specific spatial pattern of the electric field within the cross-section of a laser beam. These modes represent the different...

A technique used to measure the mode-field diameter of an optical fiber by scanning one fiber past another at a distance of five microns or less.

The laser pumping that exhibits an advantage over longitudinal pumping in that the threshold pump power density can be lowered approximately in proportion to the laser length.

The method for measuring the index profile of an optical fiber or preform by illuminating it coherently and transversely to its axis, and examining the far-field radiation pattern.

Also 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...

A measuring instrument composed of a microscope and reticle, and mounted on a calibrated slide mechanism. May be used accurately to determine the distance between objects being viewed.

The science of interfacing surfaces in moving contact, which includes areas such as friction, lubrication and wear.

Luminescence that arises from friction and that usually occurs in crystalline materials.

A compound lens consisting of two negative lenses of flint glass. A double-convex lens of crown glass is cemented between the two negative lenses. With this system, it is possible to decrease...

Computation of tristimulus values by integrating or summing, over the visible wavelength region, the product of the relative spectral power of a CIE standard source, the reflectance of the object...

In a fiber optic communications network, a circuit that connects two switching centers and does not branch off to terminal points.

Turbidity is a measure of the cloudiness or haziness of a fluid caused by the presence of suspended particles. These particles can include sediment, silt, clay, plankton, and other microscopic...

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...

An ultrafast pulsed laser is a type of laser that emits extremely short pulses of light with durations typically on the order of femtoseconds (10-15 seconds) or picoseconds (10-12 seconds). These...

The rays (such as ultraviolet rays) lying past the visible region of the spectrum.

Ultrasound used in the cleaning of metal and optical parts by virtue of its vibration rates. Large acoustic forces break off particles and contaminants from surfaces.

Ultrasonic refers to sound waves with frequencies higher than the upper audible limit of human hearing, typically above 20,000 Hz. These waves are termed ultrasonic because they are beyond the range...

Ultraviolet-C (UV-C) refers to a specific range of ultraviolet radiation with shorter wavelengths than those of visible light. UV-C radiation spans the electromagnetic spectrum with wavelengths...

Ultraviolet (UV) fiber optics refers to optical fibers that are designed and optimized for the transmission of ultraviolet light, which is electromagnetic radiation with wavelengths shorter than...