Photonics Dictionary

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 display device having a thermoplastic film as the control layer medium. The film, moving from a playoff reel, is scanned by an electron gun and melted by an RF heating unit. Deformation of the film...

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...

The greatest wavelength of radiation for a specified surface for the emission of electrons.

Time-lapse optical coherence tomography (OCT) refers to a medical imaging technique that captures a series of sequential OCT scans over time, allowing for the dynamic observation and monitoring of...

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 spectroscopic technique that combines the high chemical specificity of Raman scattering and signal sensitivity provided by surface plasmon resonance enhancement, with the nanoscale spatial...

The determination of the degree to which a manufactured component can deviate from its ideal specifications of material and geometry without impairing its performance.

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...

Topology is a branch of mathematics that focuses on the properties of space that are preserved under continuous deformations, such as stretching, crumpling, and bending, but not tearing or gluing....

A lens having one or more toric surfaces. A toric surface is one having a maximum power in one meridian and a minimum power in a perpendicular meridian. In ophthalmic optics, toric lenses are used to...

The reflection that occurs within a substance because the angle of incidence of light striking the boundary surface is in excess of the critical angle.

A transducer is a device or component that converts one form of energy into another. It is commonly used in various fields, including electronics, acoustics, and instrumentation, to facilitate the...

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...

A method of measuring total hemispherical emissivity of the plane surface of a solid that consists of thermally isolating a specimen of the material inside a vacuum, preheating it slightly above the...

A transmission electron microscope (TEM) is a powerful microscopy technique that uses a beam of electrons to create high-resolution images of extremely thin samples. In a TEM, electrons are...

A precision lens designed to convert the plane wavefront output of an interferometer to a spherical wavefront for the testing of curved (spherical) surfaces.

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 tool used in cutting circular holes around a center. Also, a laser cutter in which the beam moves in relation to the cut surface.

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

Also known as corner-cube reflector or retrodirective reflector. Three reflecting surfaces, perpendicular to each other, that are arranged like the inside corner of a cube. As the triple mirror has a...

A magnetic-deflection mass spectrometer that has an electrostatic field placed perpendicularly to its magnetic field, permitting both spatial mass dispersion and perfect double focusing in the plane...

That level of retinal illuminance resulting when a surface with a luminance of 1 candela/m2 is viewed through a pupil with an area of 1 mm2.

The process by which a surface is made to conform accurately to a given curvature.

Light that is emitted from a phosphor film applied to the surface of a three-layer thin film, respectively metal, oxide and metal.

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...

A form of liquid crystal widely used in displays, achieved by sandwiching a liquid crystal material between two substrates whose inside surfaces have been prepared with a special coating that aligns...

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 process of microphotography that involves the reduction of the original at a ratio greater than 100 to 1. The process is usually accomplished by the use of a reduced-scale negative, which, in...

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.

A light-interference device whose excitation is determined by the modulation of a light beam by an ultrasonic field.

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...

The study and photographing of microscope specimens in ultraviolet light; using an optical microscope containing fluorite and quartz components to efficiently image wavelengths much shorter than the...

Ultraviolet reflectance refers to the ability of a material or surface to reflect UV light. Ultraviolet light is electromagnetic radiation with wavelengths shorter than those of visible light,...

A term describing lenses with both surfaces finished but not yet cut to any form.

A television system designed to obtain pictures of objects or scenes beneath the surface of the water. Generally, a low-light-level television camera and a suitable light source are enclosed in a...

Equipment dependent on the effects of a vacuum. The principal applications in optics are in the coating of lenses and substrates and the fabrication of multilayer interference filters.

A vacuum chamber is a sealed enclosure from which air and other gases are removed to create a low-pressure environment, typically close to or at a complete vacuum. These chambers are often...

Also known as cathodic etching. Surface etching achieved by bombarding an evacuated surface with gas ions.

Short-distance scattering of light in holography caused by random index inhomogeneities and the developing index that interferes with the incident beam, thus recording a hologram of the scattered...