Photonics Dictionary

The series of equally spaced parallel slits that make up a scanning aperture in place of a single slit, in the scanning of a repetitive pattern.

A specific form of phase shifting interferometry - commonly referred to as multiple wavelength phase shifting interferometry - this form of interferometry utilizes two short wavelengths to synthesize...

A group of related lines that represent transitions between two spectroscopic terms, each of which may be complex. Also in physics, a multiplet is recognized as a group of related subatomic particles.

The combination of two or more signals for transmission along a single wire, path or carrier. In most optical communication systems this is referred to as wavelength division multiplexing, in which...

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...

The use of narrow bandpass filters and special photographic emulsions to discern features of a surface that would not be easily recognizable with regular black-and-white or color photographic methods.

An instrument used to record the emittance or reflectance of an object by scanning with discrete spectral resolution over a wide spectral band, or recording many discrete spectral bands...

Founded by professor Albert Munsell. In the field of colorimetry, the Munsell color system is a color space that identifies a given color based on three different color measurements. These...

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

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...

A function that quantifies the performance degradation of coherent communications systems, imaging systems and all systems that rely on the spot size of a laser beam that has propagated along an...

An LED (light-emitting diode) is a semiconductor device that emits light when an electric current passes through it. LEDs are commonly used for lighting, displays, and indicators. A NanoLED is on the...

A unit of length in the metric system equal to 10-9 meters. It formerly was called a millimicron.

A small object that behaves as a whole unit or entity in terms of it's transport and it's properties, as opposed to an individual molecule which on it's own is not considered a nanoparticle.....

A unique glass made up of nano-structured materials to create millimeter sized monolithic glass space-variant polarization converters which ultimately alter the way light propagates through and is...

The use of atoms, molecules and molecular-scale structures to enhance existing technology and develop new materials and devices. The goal of this technology is to manipulate atomic and molecular...

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....

The code used to describe the United States system of color telecasting.

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 lithography method that allows the transfer of fine-pitch gratings from a phase mask into photoresist. The exposure takes place with the light coming under an oblique angle to the mask. The...

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...

A monitoring technique used to measure the oxygen saturation levels in the brains of patients, commonly in operating room and neonatal intensive care unit settings. The technique, which is based on...

A uniaxial, birefringent crystal such as calcite or ruby in which the velocity of the extraordinary ray surpasses that of the ordinary ray. This can also be defined as the index of refraction of the...

A ghost image that has the reverse lightness relations of the original image. This phenomenon is a common optical illusion that takes place in the human visual system, following long exposures to an...

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...

Glass containing small quantities of neodymium oxide that is used as a filter plate in color television or as a lasing medium (Nd:glass) in solid-state lasers.

Literally, neodymium:yttrium-aluminum-garnet. A cylindrical rod of yttrium-aluminum-garnet doped with neodymium that is the active medium of the Nd:YAG laser, a highly serviceable solid-state device...

A cold-cathode tube containing neon and designed to visually determine a potential difference or field.

An electron tube containing neon gas that uses the transmission of an electric current through the gas to ionize the neon and produce a luminous red discharge.

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...

A computing paradigm that attempts to process information in a manner similar to that of the brain; it differs from artificial intelligence in that it relies not on pre-programming but on the...

Neurodegenerative refers to a process or condition characterized by progressive dysfunction or loss of structure and function of neurons (nerve cells) in the brain or peripheral nervous system. This...

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,...

A strip or annulus of glass coated with a semitransparent material such as inconel. The coating thickness, and as a result its transmission, varies linearly as a function of distance. The neutral...

In optics, the process of combining two lenses having equal and opposite powers to produce a result having no power.

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...