Photonics Dictionary: N

A symbol used to represent the refractive index. It is commonly used with a subscript to represent the wavelength of light.

An SI prefix meaning one billionth (10-9). Nano can also be used to indicate the study of atoms, molecules and other structures and particles on the nanometer scale. Nano-optics (also referred to as...

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...

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...

Nanoparticle photonic resonator absorption microscopy is a microscopy technique that combines the principles of photonic resonators and nanoparticle imaging to visualize and study biological samples...

Nanophotonics is a branch of science and technology that explores the behavior of light on the nanometer scale, typically at dimensions smaller than the wavelength of light. It involves the study and...

Nanopositioning refers to the precise and controlled movement or manipulation of objects or components at the nanometer scale. This technology enables the positioning of objects with extremely high...

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 defect in infrared systems that appears as a dark circular area on a displayed image, caused by radiation reflecting into a detector. It can be reduced by low-reflective coatings or by altering 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 code used to describe the United States system of color telecasting.

The light emitted from tissues without the use of fluorescent dyes as markers. Because cancerous tissues and normal tissues have differing emission spectra, the native fluorescence can be used to...

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 measurement technique used to determine the spatial distribution profile of an electrical or optical quantity of interest which is provided by multiple scans within the near-field region of a...

A near-infrared (NIR) camera is an imaging device designed to capture images in the near-infrared region of the electromagnetic spectrum. The near-infrared spectrum typically extends from about 700...

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....

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...

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....

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.

A type of thermoset rubber used to jacket fiber optic cables, including those used in outdoor military installations.

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 network interface card (NIC), also known as a network adapter or LAN adapter, is a hardware component that allows computers to connect to a local area network (LAN) and communicate with other...

A coating applied to a neutral density glass that is designed to reduce the amount of light evenly across the transmitted light spectrum with no color distortion. These coatings are designed to...

The series of rings or bands formed when light beams reflected from two polished, adjacent surfaces, placed together with a thin film of air between them, interfere. By counting these bands from the...

A device consisting of a disc with a spiral arrangement of holes that is used to convert visible patterns into electrical patterns. Light is reflected from the subject and focused through a vertical...

A pollution-measuring device used to detect the presence of nitric oxide regardless of other gases present. It utilizes the principle of laser magnetic resonance (LMR).

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...

A television system used for seeing in the dark, particularly with the use of infrared rays.

A bench with instrumentation including a collimator, a microscope, positioners and a nodal slide used to rotate a lens about its second nodal point. The nodal bench is used to determine the cardinal...

In a communications network, a point at which data are received or from which they are sent. Though the term often is used synonymously with workstation, interconnection points in a network also are...

An assembly of optical fibers that will not transmit coherent images or information because the relationship of the fibers on either end of the assembly is random; Noncoherent fiber bundles are...

Any testing method for materials and components that does not damage or destroy the test sample. Some of the methods used are x-ray, ultrasonic, electro-optic and magnetic testing.

Nonlinear polarization refers to the phenomenon where the polarization of a material responds nonlinearly to an applied electric field. In linear systems, the polarization of a material is directly...

Used in halftone screens to change the fundamental sampled spatial frequency of the halftoned picture, as well as varying the width of the pulse-modulated dots or gratings.

Sometimes referred to as the surface normal or 'surface norm'; the normal is an axis that forms right angles with a surface that light is incident upon or with other lines. The normal is used to...

Equal to 10-3 lux; used in measuring low values of illumination and luminance.

A phenomenon, exploited for medical imaging, in which the nuclei of material placed in a strong magnetic field will absorb radio waves supplied by a transmitter at particular frequencies. The energy...

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 photographic emulsion of the silver-halide type that is used to record the path of a charged traveling particle. The tracks recorded on these emulsions are typically observed under a microscope...

A lens used in the optical testing of an aspheric surface. It converts a spherical wavefront into one that precisely matches the surface under test. When the wavefront is reflected from that surface,...

Commonly performed in spectroscopy, the optical null process is a method for radiation detection whereby physical detectors are used to rapidly interchange the intensity between a reference beam and...

In image acquisition (and sampling theory), the postulate that the pickup sampling frequency must be a minimum of twice as high as the Nyquist rate of brightness change of any detail to be resolved....