Photonics Dictionary: N

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.

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...

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....

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 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...

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 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...

Radiation that does not produce free electrons and ions, or electrically charged particles.

An optical crystal that possesses a strong nonlinear dielectric response function to optical radiation. A material with a strong second-order nonlinearity must not possess a center of symmetry. See...

Nonlinear optical materials are substances that exhibit optical properties that are not linearly proportional to the intensity of incident light. In other words, these materials produce optical...

The coupling of laser or light beams via nonlinear optical techniques such as four-wave mixing to achieve spatial variation of the electrical field of the target beam. This technique is also referred...

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...

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...