Photonics Dictionary

A closely spaced series of well-known chemicals having a refractive index lying between 1.33 for water and 1.95 for a solution of phosphorus in carbon disulfide. They are used to identify powdered...

Optic surface cleaning liquid that may be applied to glass, crystal, dielectric and metal surfaces; however, may not be applied to plastic and polymer materials.

A type of liquid-crystal display in which each display element contains an active component, such as a thin-film transistor, to maintain its state between refresh scans.

When applied to LCD grids, the active matrix is a means of supplying power to pixels by use of a transistor and capacitor. The transistor functions with leads in operation with its respective row and...

A two-phase system consisting of dispersed liquid or solid particles in a gas; examples include dust, smoke and clouds.

A type of fiber optic sensor that detects alteration in position, distance, pressure, liquid level or temperature by transmitting light across a gap to a reflector; a change in the light returned to...

Attenuated total reflectance (ATR) spectroscopy is a technique used in analytical chemistry to obtain IR spectra of samples. It is particularly useful for analyzing solid and liquid samples without...

Brillouin scattering is a phenomenon in physics where an incident electromagnetic wave (usually light) interacts with acoustic phonons (quantized lattice vibrations) in a material, resulting in the...

A large tank filled with liquid hydrogen, with a flat window at one end and complex optical devices for observing and photographing the rows of fine bubbles formed when a high-energy particle...

The photographic recording of gas bubbles produced when particles traverse liquid hydrogen in a bubble chamber.

The creation of a diode laser structure by liquid-phase epitaxy over a grooved substrate.

The state of a liquid crystal in which the molecules are arranged in layers with their long axes in the plane of each layer. The alignment in each layer is parallel and the alignment in adjacent...

The monochromatic transparency effect produced by the immersion of a finely powdered substance (e.g., glass or quartz) into a liquid with a similar refractive index.

A transparent powdered solid immersed in a liquid or plastic of similar refractive index but widely different dispersion; used to isolate narrow spectral regions.

A computer-generated hologram (CGH) is a holographic image produced using computational methods and algorithms, rather than traditional optical techniques. CGHs are generated entirely in digital form...

A liquid, usually of a specific refractive index and dispersion, serving as an interface between two solids to form a complete light transmission system.

The radiation spectrum of matter found in condensed states, liquid or solid, that is continuous and not a line spectrum. The details of this spectrum are almost independent of the matter emitting the...

The ability of particular pure liquids to doubly refract when influenced by a magnetic field with a direction that is transverse to the light beam.

Intense scattering in the region of the liquid-gas critical point. At this point the gas will strongly scatter all light to create a vivid opalescent appearance.

A vacuum pump in which pressure is reduced by condensing gases on surfaces cryogenically cooled to about 20 K (liquid hydrogen) or 4 K (liquid helium).

Custom lapping and polishing services involve specialized processes used to improve the surface finish and dimensional accuracy of components to meet specific requirements or standards. These...

The selective absorption of electromagnetic waves by a liquid made up of molecules with permanent dipole movement.

A device used in ultrasonic imaging to measure the velocity and attenuation of compressional waves in a transparent liquid by virtue of acoustic waves set up in the liquid. The wavefronts serve as a...

Any of the constants that relate the tendency of the director to remain parallel to restoring torques throughout the media. The three constants of importance in liquid crystal displays are: splay --...

A tank with a boiling solvent at the bottom and a ring of cold piping higher up that condenses the liquid and returns it to the bottom. Objects such as lenses or small metal parts to be cleaned are...

Description of a material, such as a water-soluble salt, that will continue absorbing moisture from the surrounding atmosphere until it dissolves into a liquid.

An evacuated, double-walled container for storing liquids at low temperatures. Often made of glass, the vessel resembles a Thermos bottle.

Dewetting is a phenomenon in materials science and physics where a thin film or coating spontaneously undergoes a process of breaking up and forming isolated droplets on a substrate. This occurs due...

A type of photographic film, often used in microfilming, that is processed by heat treatment, needing no liquid application.

An instrument used to measure expansion of solids, liquids and gases.

In a liquid crystal system, the director refers to the local symmetry axis around which the long range order of the liquid crystal is aligned. In the case of the nematic phase, the molecular long...

A microscope objective designed to be used without liquid between the cover glass and the objective, or, in the case of metallurgical objectives, between the objective and the specimen.

The nonthermal conversion of electrical energy into light in a liquid or solid substance. The photon emission resulting from electron-hole recombination in a PN junction is one example. This is the...

A high-speed shutter, similar to a Kerr cell, that uses the birefringence produced in a liquid during the passage of an electric current through it to change the liquid's optical transmission...

An EMCCD (electron-multiplying charge-coupled device) camera is a type of scientific camera specifically designed for low-light imaging applications that require high sensitivity and fast readout...

An electrophoretic display, often referred to as an electronic paper display or e-paper display, is a type of electronic visual display technology used in electronic devices for the purpose of...

The movement of particulate material by flowing gas or liquid.

A well controlled thin films technique for growing films with good crystal structure in ultra high vacuum environments at very low deposition rates. Epitaxy methods are well known for the growing of...

An acid used to etch the surfaces of particular materials. For glass, hydrofluoric acid is used either as a liquid or a vapor. Metals are etched by means of suitable acids or other liquids, often to...

A process, either naturally occurring or mechanically induced, whereby water is changed from its liquid state into a vapor.

An electronic display in which a flat screen is formed by an orthogonal array of display devices, such as electroluminescent devices, light-emitting diodes or liquid crystal cells.

Flow chemistry, also known as continuous-flow chemistry, is a chemical manufacturing process where reactions take place in a continuous stream of fluids (liquids or gases) rather than in batch...

A method of synthesis for crystals such as KTP. The process involves the use of a high-temperature solution called flux to enable crystal growth. Flux dissolves the elements of the desired crystal,...

FTIR (Fourier transform infrared) spectrometer is a powerful analytical instrument used to obtain an infrared spectrum of absorption or emission of a solid, liquid, or gas sample. It operates based...