Photonics Dictionary

Microscopy is a scientific technique that involves the use of microscopes to observe and study objects that are too small to be seen with the naked eye. Microscopes are instruments that magnify and...

Mie scattering, named after the German physicist Gustav Mie, refers to the scattering of electromagnetic radiation (such as light) by spherical particles. Unlike Rayleigh scattering, which is...

Minimum object distance, often abbreviated as MOD, refers to the closest distance at which a camera lens or optical system is capable of producing a sharp and focused image. In photography, this term...

The distortion of an object's true image as the result of abnormal atmospheric disturbances along the path traveled by the light. The atmospheric disturbances common with mirages are a result of a...

A mixed-signal oscilloscope (MSO) is a type of electronic test instrument that combines the capabilities of both a traditional oscilloscope and a logic analyzer. It is designed to capture and display...

In an optical system, noise created by mode-dependent optical losses and variations in the distribution of radiant power among the modes or relative phases of the modes. Also known as speckle noise.

A multimode laser characteristic defined as the ratio of power loss for the second mode to that of the lowest mode.

Modified chemical vapor deposition (MCVD) is a technique used in the fabrication of optical fibers. It is a specialized form of chemical vapor deposition (CVD) that is employed to produce...

Contour mapping technique that involves positioning a grating close to an object and observing its shadow on the object through the grating. The resultant moiré fringes correspond to a contour line...

In optics, a motion controller refers to a device or system that precisely controls the movement of optical components, such as mirrors, lenses, stages, or other elements within an optical setup. The...

A metal-semiconductor-metal (MSM) photodiode is a type of photodetector that consists of metal electrodes on a semiconductor material. Unlike the more common PIN photodiodes, which have a P-type and...

A hologram formed by reconstruction of multicolor wavefronts. The system used to produce the hologram is designed to combine the different colored wavefronts of the separate illuminating sources, and...

Nanoplasmonics is a branch of nanophotonics that focuses on the study and manipulation of optical phenomena at the nanoscale using plasmonic materials and structures. Plasmonics deals with the...

An imaging system designed to highlight small deviations in a planar reflective object such as a mirror. The system can be used to detect minute flaws or to image faint marks that are made in the...

The closest distance to which the eye can focus on an object, normally taken to be 250 mm. The near point varies with age.

The area closest to an aperture or source where the diffraction pattern differs substantially from that observed at an infinite distance, or more specifically, the far field. Also referred to as the...

The nondestructive analysis and recording of industrial components based on the absorption of relatively low-energy neutrons by material having low atomic numbers. The visible image formed by the...

An instrument devised by Nichols and Hull for use in the measurement of radiation pressure. The device has two small silvered, glass mirrors that are suspended, in the way of a torsion balance, by a...

A prism invented by William Nicol in 1828 that is made of calcite, the end faces of which are ground to an angle of 68° between one vertical side and the end surface. The prism is cut diagonally...

Also referred to as a band-stop or band rejection filter; a notch filter is a filter that is designed to screen out a very narrow band of radiation by transmitting most wavelengths with little...

A chemical detection technique used to measure molecules that have a magnetic dipole moment. The analysis is directed to nucleuses which have a quadrupole moment which leads to an asymmetric electric...

A form of high-power microscope objective where the space between the object and the first element is filled with an oil having the same index as that element. This form reduces losses, increases the...

Optical artifacts refer to undesired or unintended effects that can occur in optical systems, such as microscopes, cameras, telescopes, and other optical instruments. These artifacts can distort or...

Optical cements and adhesives are specialized materials used in the assembly and bonding of optical components in optical systems. These materials are designed to provide secure and durable bonds...

The adhesion of two sufficiently clean and close-fitting surfaces without the use of cement or glue. The optically contacted surface is almost as durable as the body of the glass, and the surfaces...

An instrument used to measure backscatter as well as optical return loss and reflectance within an optical fiber system by measuring the reflected light when a continuous wave is transmitted through...

Optical fiber optic switches are devices used in optical fiber communication systems to selectively route optical signals from one input fiber to one or more output fibers. They play a crucial role...

Optical fiber is a thin, flexible, transparent strand or filament made of glass or plastic used for transmitting light signals over long distances with minimal loss of signal quality. It serves as a...

Optical glass refers to a type of glass specifically engineered and manufactured for use in optical components and systems, such as lenses, prisms, mirrors, and filters. Optical glass is...

An optical grating, in the context of optics and physics, refers to a device with a periodic structure of closely spaced, parallel slits or rulings. These slits or rulings act as obstacles to the...

An optical time-domain reflectometer (OTDR) is a specialized instrument used in optical fiber communications to characterize and analyze the optical fibers' characteristics, including attenuation,...

Point at which a laser's material gain is equal to, or greater than, the circuit losses.

A record formed when the luminous trace or image produced by an oscilloscope is photographed.

An instrument used to record rapidly varying currents or voltages. An oscillograph may consist of a cathode-ray tube oscilloscope with a camera attachment, or a mirror galvanometer with a lamp and...

The graphic recording of physical changes vs. time, in electrical quantities, using an oscilloscope.

A system in which a supplied signal causes the deflection of the electron beam in a cathode-ray tube, thus forming a visible trace on the phosphor screen of the tube and providing for examination of...

An otoscope is a medical device used by healthcare professionals, particularly ear, nose, and throat (ENT) specialists, primary care physicians, and pediatricians, to examine the ear canal and...

1. In a photonic interconnect, the number of detectors in a given area. Detectors spaced too closely may give rise to crosstalk. 2. In the cross section of a fiber optic bundle, the ratio of fiber...

A lens system that is capable of producing a 360° image, or one that is very close to that. In recording, the image may be formed on a curved strip of film surrounding the lens, resulting in a...

A ray that behaves according to paraxial equations; one that lies close to and almost parallel to the optical axis.

A passive optical network (PON) is a telecommunications network architecture that uses optical fibers and passive optical components to provide high-speed broadband services to end-users. In a PON...

Photobleaching is a phenomenon in which the fluorescence of a fluorophore (a fluorescent molecule or dye) is permanently reduced or eliminated upon prolonged exposure to light. This process occurs...

The effect that the optical losses in a medium can grow when the medium is irradiated with light at certain wavelengths.

A relay that opens or closes an electrical circuit depending on the intensity of the light incident to a photoelectric device contained in the relay.