Photonics Dictionary

Light consisting of a single wavelength or a very narrow band of wavelengths.

A camera equipped with a lens and a long length of perforated film, the latter being moved intermittently between exposures by a pulldown claw or sprocket. A rotating shutter serves to cut off the...

A lens with internally adjustable elements to produce a range of focal lengths. Unlike a true zoom lens, a multifocal lens must be refocused each time the focal length is changed. See variable-focus...

A multihaul transceiver is an optical transceiver module designed to support multiple network architectures or transmission technologies within a single compact device. It offers versatility and...

A fiber optic bundle split along its length with the ends of the fibers extending separately to illuminate different points with a single light source.

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...

Alphanumerical description of color according to Munsell hue, value and chroma.

Nanoimprint lithography (NIL) is a nanolithography technique used for fabricating nanoscale patterns on a substrate. It is a high-resolution, high-throughput process that involves the mechanical...

Nd:YAG laser refers to a solid-state laser that utilizes neodymium-doped yttrium aluminum garnet (Nd:Y3Al5O12) as the gain medium. This type of laser emits light at a wavelength of 1064 nm in the...

A scanning probe microscope that analyzes the surface of a specimen by recording the intensity of light as it is focused through a pipette and raster scanned across the specimen at a distance less...

A near-infrared (NIR) spectrometer is an analytical instrument used to measure the absorption, transmission, or reflection of light in the near-infrared region of the electromagnetic spectrum....

Near-infrared spectroscopy (NIRS) is a non-invasive analytical technique that uses the near-infrared region of the electromagnetic spectrum to study the absorption of light by molecules in a sample....

A form of liquid crystal with an appearance of moving, threadlike structures, particularly visible when observed in thick specimens with polarized light. During this phase, the molecules of the...

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...

Neuromorphic refers to the design and development of computing systems or devices that are inspired by the structure and functioning of the human brain and nervous system. The term is derived from...

A neuromorphic vision sensor is a type of imaging device designed to mimic the structure and functioning of the human visual system. Inspired by the biological principles of the human eye and brain,...

Prediction based on observations of nuclear masses in the valley of stability that indicates the maximum number of electrons that will bind with a given number of protons in progressive order along...

A telescope with a concave paraboloidal objective mirror and a small plane (diagonal) mirror that reflects rays from the primary mirror laterally outside the tube where the image is viewed with an...

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...

A nitrogen vacancy (NV) refers to a specific type of defect or impurity in a crystal lattice where a nitrogen atom replaces a carbon atom adjacent to a vacancy (an empty lattice site) in the diamond...

Of all the rays passing through a lens from an off-axis object point to its corresponding image point, there is always one ray whose direction in the image space is equal to that in the object space....

The unwanted and unpredictable fluctuations that distort a received signal and hence tend to obscure the desired message. Noise disturbances, which may be generated in the devices of a communications...

Nonlinear optics is a branch of optics that studies the optical phenomena that occur when intense light interacts with a material and induces nonlinear responses. In contrast to linear optics, where...

A hemispherical covering that is rotatable about a central axis. There is a slit opening along one side wide enough to allow a telescope to be directed at any vertical angle up to 90°.

A prism or prism assembly that serves to displace the instrument's optical axis.

The phenomenon that can render an optical resonator the equivalent of a semiconductor flip-flop. A bistable device will remain stable in two optical states, one of high transmission and another of...

Optical character recognition (OCR) is a technology that is used to convert printed or handwritten text into machine-readable text. OCR software and systems are designed to recognize and extract...

An optical clock is a highly precise and advanced timekeeping device that relies on the oscillations of electromagnetic radiation in the optical or ultraviolet part of the electromagnetic spectrum....

An optical filter is a device that selectively transmits or blocks specific wavelengths, or colors, of light. Optical filters are used to control the spectral content of light in various...

An optical gate typically refers to a device or system that controls the transmission of light, allowing it to pass through or be blocked in a manner analogous to an electronic gate controlling the...

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 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...

An instrument that measures several optical parameters, such as optical power and wavelength, with a single measurement input.

Also known as a white-light interferometer. Measures surface texture and shape from nanometer-scale roughness to millimeter-scale step heights. A standard arrangement includes an illumination source,...

Optical switching refers to the process of controlling the routing or transmission of optical signals within a network using various techniques to selectively switch or redirect optical paths. This...

A method for characterizing a fiber wherein an optical pulse is transmitted through the fiber, and the resulting light scattered and reflected to the input is measured (by an optical time-domain...

Sets of paired lines carefully designed to give the most accurate pointing possible for various lengths of sight.

Optical tweezers refer to a scientific instrument that uses the pressure of laser light to trap and manipulate microscopic objects, such as particles or biological cells, in three dimensions. This...

Optoacoustic, or photoacoustic, refers to a phenomenon and related techniques that involve the generation of acoustic waves in a material induced by the absorption of light. The term "optoacoustic"...

Any organic substance, that when dissolved in appropriate liquid based solvents will absorb and emit electromagnetic radiation in the near ultraviolet, visible and near infrared spectral regions....

An organic light-emitting diode (OLED) is a type of light-emitting diode (LED) technology that utilizes organic compounds to produce light. OLEDs are commonly used in display technologies, such as...

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...

A projector used to project transparencies. A horizontal 8 x 10-in. stage for writing or laying down preformed transparencies is provided with either an elliptical mirror or a plastic Fresnel lens...