Photonics Dictionary

A device used to take turbidimetric or nephelometric measurements by considering the contrast between a constant brightness field and an illuminated line positioned behind the solution being tested.

Second-harmonic generation (SHG) is a nonlinear optical process that occurs when two photons with the same frequency combine within a nonlinear material, resulting in the generation of a new photon...

Self-phase modulation (SPM) is a nonlinear optical phenomenon that occurs when an intense laser beam passes through a medium, causing a change in the phase of the light due to its interaction with...

An instrument that uses a blackened silver-disc reflector with a shutter to create temperature fluctuations that are proportional to the intensity of the solar radiation incident upon it. Using the...

A technique for observing the decay of light emissions from sources following their pulsed excitations, based on recording the arrival time of the first photoelectron after excitation. After many...

In micropositioning, a remote positioning device in which an electric current drives a movable armature mounted on an electromagnetic coil.

An instrument for plotting the rotatory dispersion of a substance at different wavelengths.

Radiation emitted when a quantum mechanical system drops spontaneously from an excited level to a lower level. This radiation is emitted according to the laws of probability without regard to the...

In local area networking, arrangement of the satellite nodes around a central node through which all routing of network data takes place.

Radiation similar in origin to spontaneous emission but determined by the presence of other radiation having the same frequency. Because the phase and amplitude of the stimulated wave depend on the...

The determination of what, how much and in what proportions chemicals must be combined to produce the desired reactions and products.

A copolymer of styrene and acrylic used in molded optical components; it has a high refractive index and a low coefficient of thermal expansion.

Superluminal transmission refers to the hypothetical process of transmitting information faster than the speed of light, which is commonly denoted as superluminal or faster-than-light (FTL)...

The 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.

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 time-to-amplitude converter (TAC) is an electronic circuit that converts a time interval between two events into an amplitude or voltage signal. TACs are commonly used in various scientific and...

A symmetrical, very wide-angle lens. Well-corrected for spherical aberration and color, the Topogon can cover fields up to 90° at speeds from f/11 to f/6.3.

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....

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.

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...

Two-photon polymerization (TPP) is a technique used in additive manufacturing, specifically in the field of 3D printing. It involves using a focused laser to polymerize a photosensitive material in a...

A vortex phase plate is an optical device designed to impart a phase singularity, commonly referred to as a vortex or phase vortex, onto a light beam. This singularity results in a phase profile...

Electromagnetic energy is transmitted in the form of a sinusoidal wave. The wavelength is the physical distance covered by one cycle of this wave; it is inversely proportional to frequency.

A photometer that uses a wedge, marked to show its reduction of flux density, to make two light sources equal in intensity for comparison of luminous intensities. This is accomplished by the gradual...

In micropositioning systems, motion (most frequently undesired) about the Z-axis.

The constant equal to the unit stress divided by unit deformation, relative to all values and a substance's proportional restrictions.

A plate of glass, usually a photograph, on which there is a central spot surrounded by concentric annular zones, alternately opaque and transparent, the radii of the boundaries between the zones...