Photonics Dictionary

Infrared optics refer to optical components and systems designed to manipulate and control infrared (IR) light, which lies beyond the visible spectrum. These components are crucial for various...

Infrared (IR) refers to the region of the electromagnetic spectrum with wavelengths longer than those of visible light, but shorter than those of microwaves. The infrared spectrum spans wavelengths...

A semiconductor device with a semiconductor junction in which infrared radiant flux is nonthermally produced when a current flows as a result of applied voltage.

Instantaneous field of view (iFOV) is a term commonly used in the context of remote sensing, imaging systems, and optical instruments. It refers to the specific portion of a scene that an optical...

A material often used in the construction of optical instruments because of its low coefficient of thermal expansion (0.9 x 10-6/ °C).

A device designed to measure radiant energy, particularly in the thermal region.

An atmospheric nonlinear process unique to CO2 laser wavelengths, whereby CO2 absorbs 10.6-µm radiation and the CO2 molecules in the (100) vibrational state are excited to the (001) level, and...

For any point on a thermal radiator, at thermal equilibrium and for each wavelength, the emissivity in any direction is equal to the absorptance for radiation from the same direction.

Westinghouse trade name for an alloy of iron, nickel and cobalt, which has the same thermal expansion as glass and therefore is often used for glass-to-metal or ceramic-to-metal seals.

Laser ablation is a process that involves the removal or erosion of material from a target surface using laser energy. This technique is widely used in various scientific, industrial, and medical...

Laser annealing is a process that involves using a laser beam to heat and modify the microstructure of a material, typically a thin film or surface layer, with the objective of improving its...

Device that operates by interaction of incident radiation with semiconductor based material in order to produce an electrical signal or by other means, to interact with calorimetric devices which...

Long-wave infrared (LWIR) refers to a specific range of the infrared spectrum. Infrared radiation is divided into three main categories based on wavelength: near-infrared (NIR), mid-wave infrared...

A colorless, crystalline compound whose low refractive index (n = 1.38) makes it effective as a lens antireflection coating when deposited by thermal evaporation in a near vacuum. This process...

A magnon is a quasiparticle representing a quantized spin wave in a magnetic material. In other words, it is a collective excitation of the spins of electrons in a magnetic solid, analogous to the...

In the context of thin film deposition processes such as evaporation or sputtering, masks are used to selectively deposit material onto substrates, creating patterns or structures with precise...

A fiber splice accomplished by fixtures or materials, rather than by thermal fusion. Index matching material may be applied between the two fiber ends.

Metasurfaces are two-dimensional arrays of subwavelength-scale artificial structures, often referred to as meta-atoms or meta-elements, arranged in a specific pattern to manipulate the propagation of...

A mid-infrared camera is a type of imaging device designed to capture images in the mid-infrared (mid-IR) spectral range, typically spanning wavelengths from approximately 3 to 12 µm. This...

MWIR stands for mid-wave infrared, referring to a specific range of wavelengths within the infrared spectrum. Infrared radiation is categorized into three main regions based on wavelength:...

In a thermal imaging system, the smallest change in blackbody equivalent temperature that can be detected clearly by the system as a function of target frequency.

A form of laser output noise that is caused by thermal, mechanical, or acoustical disturbances of the cavity length. Mode sweeping occurs when the length of the laser cavity changes as a result of...

Multispectral imaging is a technique that involves capturing and analyzing images at multiple discrete spectral bands within the electromagnetic spectrum. Unlike hyperspectral imaging, which acquires...

A form of shearing interferometer that contains a simple wedged (plane-parallel) glass plate with a nonzero optical path difference to create interference between split optical wavefronts. The...

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...

A nanotube, also known as a nanotubule or simply a tube-like structure, is a nanoscale cylindrical structure composed of various materials, including carbon, boron nitride, or other compounds....

A Nernst glower, also known simply as a Nernst lamp or Nernst filament, is a type of incandescent lamp or radiant heater based on the Nernst effect. It was invented by the German physicist and...

Any noise or current fluctuation that prevents precise measurement of the signal current. Both dark current and signal current have random fluctuations that affect the arrival of pulses. Thermal...

In a thermal imaging system, the change in temperature that yields a signal-to-noise ratio of unity.

A nonradiative transition refers to a process in which an electron or an atom undergoes a change in its energy state without emitting a photon. In contrast to radiative transitions, where a photon is...

Also known as a gray body; a nonselective radiator is a thermal radiator that has a constant spectral emissivity with respect to wavelength throughout the spectral range being considered. 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...

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...

Optical manufacturing tools and machinery encompass a wide range of equipment, instruments, and systems used in the fabrication, shaping, finishing, and testing of optical components and systems....

Optical materials refer to substances or compounds specifically chosen for their optical properties and used in the fabrication of optical components and systems. These materials are characterized by...

Optical noise refers to undesirable fluctuations or disturbances in an optical signal that can affect the quality or integrity of the transmitted information. This type of noise is particularly...

The emission of gas or de-aeration due to thermal variations and often occurring in a vacuum. In a cleanroom, contamination from the spontaneous emission of absorbed particles.

A Peltier cooler, also known as a thermoelectric cooler (TEC) or thermoelectric module, is a solid-state device that uses the Peltier effect to transfer heat between two electrical junctions. It can...

A phonon is a quantum of vibrational energy associated with the periodic motion of atoms or molecules in a crystalline lattice. In simpler terms, phonons are quanta of lattice vibrations in a solid...

A light therapy that utilizes nonionizing light sources, including lasers, LEDs, and broadband light, in the visible and infrared spectrum. It is a nonthermal process involving endogenous...

The term photochemical pertains to chemical processes or reactions that are initiated or influenced by the absorption of light. Photochemical reactions involve the interaction of light, often in the...

An optical medical instrument that uses an intense, precisely focused beam of light to stop weakened blood vessels from hemorrhaging. The thermal effect of the beam strengthens the weakened vessels...

Phototheranostics, a portmanteau of "photo" (light), "therapy," and "diagnostics," refers to an emerging field that combines therapeutic and diagnostic capabilities in a single platform, often...

A vacuum gauge designed to measure very high degrees of vacuum by thermal conduction.

Plastic optics refers to optical components or systems that are made from transparent plastic materials, as opposed to traditional optical components made from glass or other materials. Plastic...

A device used to detect radiant energy by means of the thermal expansion of gas.