Definitions: N

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

In a semiconductor, the state created by the addition of a dopant that provides excess electrons.

A quadrivalent semiconductor material, with electrons as the majority charge carriers, that is formed by doping with donor atoms.

In a remote sensing system, nadir refers to the point on the ground located vertically below the center of the system. In astronomy, the nadir is the vertical direction that points towards the force...

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...

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.....

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 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....

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...

An optical pyrometer that is equipped with a narrow bandpass filter to transmit a limited number of wavelengths to the sensing device.

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...

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 longest wavelengths of the ultraviolet region, nominally 300 to 400 nm.

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 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...

In a laser diode, lateral motion of the beam center at the facet when the drive current is changed.

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....

The shortest wavelengths of the infrared region, nominally 0.75 to 3 µm.

A light source, such as the sun or an incandescent lamp, that freely penetrates ordinary glass bulbs and emits in the near-ultraviolet (wavelengths ranging from about 300 to 400 nm). A mercury vapor...

A resampling and interpolation method that uses only the value of the nearest neighbor pixel, while not considering values from any other neighboring pixels from the source image to determine the...

Amplification; the result of the excess of stimulated radiation over absorbed radiation.

The structure that holds the photographic negative in a proper position that is both flat and parallel to the lens plane, as well as being placed in a fixed position that is the right distance from...

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...

State typically studied in liquid crystals in which the dielectric coefficient parallel to the director is less than the dielectric coefficient perpendicular to the director.

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...

In a cold-cathode tube, the luminance between the cathode dark space and the Faraday dark space. In a vacuum tube, the luminance between the Crookes dark space and the Faraday dark space.

When a stereo pair of images is switched so that the right eye sees the left image and the left eye the right, the stereo image perceived will be reversed in terms of relative object depth.