Photonics Dictionary

Plasmonics is a field of science and technology that focuses on the interaction between electromagnetic radiation and free electrons in a metal or semiconductor at the nanoscale. Specifically,...

Plastic optics refers to optical components or systems that are made from transparent plastic materials, as opposed to traditional optical components made from glass or other materials. Plastic...

In optics, the Pockels effect refers to the phenomenon where the refractive index of a material changes in response to an applied electric field. This effect is utilized in Pockels cells, which are...

A polariton is a quasiparticle resulting from the strong coupling between photons (light particles) and certain types of excitations in a material, such as electronic excitations (electrons and...

Polarization refers to the orientation of oscillations in a transverse wave, such as light waves, radio waves, or other electromagnetic waves. In simpler terms, it describes the direction in which...

The process of aligning the crystallites in a piezoelectric material by placing a large DC field across the element at an elevated temperature. The alignment of crystallites results in an increased...

Polymers are large molecules composed of repeating structural units called monomers. These monomers are chemically bonded together to form long chains or networks, creating a macromolecular...

A medical imaging device that uses a ring of crystal/photomultiplier tube assemblies encircling the patient to detect gamma rays emitted by positrons colliding with electrons.

Basically, a hydrogen atom with two alterations, positronium is the lightest atom in the universe and has an extremely light positron in its nucleus that replaces hydrogen's proton so that its atomic...

A crystalline material with a high electro-optic coefficient, capable of operating at short wavelengths, with applications in laser, optical disc, printing and microwave systems.

A device designed to measure electromotive force or electrical difference potential.

Power modulation refers to the intentional variation of power levels in a signal, often in the context of electronic communication systems. This modulation technique is used to encode information...

For an electromagnetic field mode varying sinusoidally with time at a given frequency, the logarithmic rate of change, with respect to distance in a given direction, of the complex amplitude of any...

A planar photocathode and a planar phosphor screen mounted in a close-spaced parallel configuration in an evacuated enclosure so that the ensemble of photoelectrons emitted from each photocathode...

The instrument used to analyze a pulsed electromagnetic wave to determine its time, amplitude, duration and shape, and to display this information in some appropriate form, either visually or...

Device in which contact ionization of atomic particles and thermionic electron emission are used to produce magnetically confined plasma that is greatly ionized.

A device used in electron microscopes and particle accelerators to focus electron beams by the arrangement of four electrodes of alternating signs around the electron beam.

A quantum cascade laser (QCL) is a type of semiconductor laser that operates based on the principles of quantum mechanics. It is a versatile and powerful device used for emitting coherent light in...

Quantum confinement refers to the phenomenon in quantum mechanics where the motion of charge carriers, such as electrons or holes, is restricted to a region of space that is smaller than their...

A photodetector in which an electrical charge is produced when incident photons change electrons within the detecting material from nonconducting to conducting states. See photoconductive detector;...

Quantum dot light-emitting diode (QLED) is a display technology that utilizes quantum dots, which are semiconductor nanocrystals, to produce vibrant and high-quality images. QLED displays are...

A quantum dot is a nanoscale semiconductor structure, typically composed of materials like cadmium selenide or indium arsenide, that exhibits unique quantum mechanical properties. These properties...

Quantum efficiency (QE) is a measure of the effectiveness with which a device or system, typically in the context of photonics or electronics, converts incoming photons (light) into a useful output...

A quantum well is a structure in quantum mechanics that confines particles, such as electrons or holes, in one spatial dimension. This confinement leads to quantized energy levels, creating a...

A spectrograph used to detect radiation in the range of the ultraviolet in the electromagnetic spectrum. It is made up of quartz because that material, unlike regular glass, is not opaque to the...

Rabi oscillations are a fundamental phenomenon in quantum mechanics that describe the periodic and reversible exchange of energy between two quantum states when subjected to an oscillating external...

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,...

Raster scanning is a technique used in imaging and scanning systems to systematically capture and process information from a two-dimensional area or surface. It involves moving a sensor or scanning...

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...