Photonics Dictionary: R

The spontaneous visual presentation of radar information by electronic traces on a cathode-ray tube.

Pertaining to electromagnetic radiation, with the contributions at all wavelengths of interest weighted equally.

The energy passed on as electromagnetic radiation; e.g., radio, heat or light waves.

Any of the many devices used to detect the presence of radiation from a specific region of the electromagnetic spectrum.

The detection and analysis of naturally formed extraterrestrial electromagnetic radiation within the radio frequency range of the spectrum.

An instrument designed to collect naturally formed extraterrestrial electromagnetic radiation within the radio frequency range of the spectrum in amounts sufficient to be measured.

A gas laser in which the electrodes are mounted perpendicular to the optical resonator.

A very uncommon lamp in which a tungsten electrode is heated to incandescence by a radio-frequency electrical current.

A device used to accelerate the electrons in a free-electron laser by channeling microwave energy into waveguide cavity assemblies.

An instrument used to detect radioactive materials: alpha particles or helium nuclei; beta particles or free electrons; and gamma rays, which are x-rays of very short wavelength. They may be detected...

A solid-state panel of the photoconductor-electroluminescent type. The photoconductive layer, sensitive to x-rays, is coated by the electroluminescent, which gives the visible image. When the former...

Rare earth dopants refer to elements from the lanthanide series, also known as rare earth elements, that are intentionally introduced into the crystal lattice of a material to modify its properties....

Rare-earth elements (REEs) are a group of seventeen chemical elements found in the Earth's crust, characterized by their unique properties and scarcity relative to other elements. Despite their name,...

An electronic device that minimizes short-term drift effects and random measurement error inherent in alternate ellipsometric measurement of two signals.

Reactive evaporation refers to a process in thin-film deposition where a material is deposited onto a substrate through evaporation, and chemical reactions take place during or after the evaporation...

In chemistry, a device in which a chemical reaction takes place. In electronics, a device that introduces reactance into a circuit.

A detector and signal demodulator used in optical communications systems to receive a signal and often to translate it into an electronic signal.

Recombinase polymerase amplification (RPA) is a molecular biology technique used to rapidly amplify specific DNA or RNA sequences under isothermal conditions, meaning it does not require the...

The radiation emitted in semiconductors when electrons in the conduction band recombine with holes in the valence band. If population inversion occurs between portions of the valence and conduction...

RGB stands for red, green, blue, which are the primary colors of light used in additive color mixing. The RGB color model is widely used in various electronic displays, such as computer monitors,...

Reflectance spectroscopy is a technique used to analyze the reflective properties of materials across various wavelengths of the electromagnetic spectrum. By measuring the reflectance of light from a...

Remote inspection refers to the process of inspecting, evaluating, or monitoring assets, equipment, infrastructure, or systems from a distance, typically using remote sensing technologies and...

Remote sensing is a method of data collection and observation where information about objects, areas, or phenomena on Earth's surface is gathered from a distance, typically using sensors onboard...

Resonance can be defined in various contexts, including physics, chemistry, and music. Here are definitions for resonance in a few different fields: Physics: In physics, resonance refers to the...

A resonator is a device or system that exhibits resonance, which is a phenomenon that occurs when an external force or stimulus is applied at a specific frequency, causing the system to oscillate...

The number of electrons emitted per photon incident upon a photodetector.

A reticle, also known as a reticule or graticule, is a pattern or set of markings placed in the focal plane of an optical instrument, such as a microscope, telescope, riflescope, or camera, to...

A retroreflector is an optical device or structure that reflects incident light or electromagnetic waves back to their source, regardless of the direction from which the light approaches. Unlike...

Conductor element for use in integrated electro-optic systems that measures current flowing through it.

Developed for use in military reconnaissance systems, it consists of a polygonal mirror, drive motor, interface between motor and mirror, and control electronics. Also used in broadband video...

A ruticon is an opto-electronic device in which light going through it can be modulated by an electric field. The intensity distribution of the resulting image can be precisely controlled....

The term "Rydberg atom" refers to an atom in a highly excited state where one or more of its electrons are in a Rydberg orbital. A Rydberg atom is characterized by having an electron orbit that is...