Photonics Dictionary

Plasmon ion-assisted deposition (PIAD) is a technique used in thin-film deposition processes, particularly in the production of optical coatings. This method combines two key processes: plasmon...

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,...

Pluggable optics, also known as pluggable transceivers or optical transceivers, are modular devices used in optical communication systems to transmit and receive data over optical fibers. They are...

A point cloud is a set of data points in a three-dimensional coordinate system, where each point represents a specific location in space. These points are typically obtained through various sensing...

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...

A subsurface imaging technique based upon the polarization of light reflected off an object. The polarization of reflected light gives information about the object's absorption properties that...

Single-mode fiber that preserves the plane of polarization of the light launched into it as the beam propagates through its length. Also called polarization-maintaining fiber. The polarization is...

A mold for glass or plastics often made of stainless steel to prevent pitting or oxidation in service. It is polished to the opposite curve of the surface that will be molded, and may be spherical or...

The process of forming a polisher by pressing it with an optical surface.

The optical process, following grinding, that puts a highly finished, smooth and apparently amorphous surface on a lens or a mirror.

In fiber optics, a device used to polish a biconic plug to a specified length and surface finish. Also called a polishing disc.

A polygonal mirror, also known as a multifaceted mirror or facet mirror, is a type of optical component used in various laser systems, optical scanners, and imaging devices. It consists of a flat or...

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 45-90-45° reflecting prism whose surfaces form the 90° angle reflecting the light beam through a total angle of 180°. The corners of the prism are rounded to minimize breakage and simplify...

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...

A blank having basic surface curves attained by forming heat-softened glass that is pressed in a mold.

In a waveguide, the material in intimate contact with the cladding surface, applied to preserve the integrity of that surface.

A straight line connecting the curvature centers of the refracting lens surfaces. In a mechanical sense, a line joining the centers of a lens as it is placed in a mount. The principal axis is the...

In a lens or lens system, that surface at which the projections of an entering and exiting ray intersect. Also known as the equivalent refracting surface, the principal plane is most often not...

The thin edge of a refracting prism; the line of intersection of two refracting surfaces of a prism.

A prism is a geometric optical element with flat, polished surfaces that refract light. It is typically a solid, transparent object with at least two flat surfaces that are inclined relative to each...

A probe card is a testing device used in the semiconductor manufacturing industry to evaluate and test the electrical characteristics of integrated circuits (ICs) on a wafer. Its primary function is...

Measurement of surface roughness or quality through the use of a diamond-pointed stylus connected to a coil in an electric field. As the stylus is traced across the surface, a current is created that...

The measurement of surface temperature by a thermograph that forms a pattern of the heat radiated by the surface on a luminescent screen.

An assembly of prototype instruments, equipment and/or software designed to perform all the functions of a concept or idea which, when operated as a system, produce evidence, results or data...

A film applied to a coated or uncoated optical surface primarily for protecting this surface from mechanical abrasion, from chemical corrosion, or from both. For example, a thin layer of silicon...

Factor that relates the pulse spread occurring in a graded-index fiber to that of an equivalent step-index fiber having an identical refractive index difference between core and cladding (that is, an...

The use of variations in the power supplied to a laser to change the shape of the output pulse. The technique is used in laser welding, for example, to condition a surface by preheating it at a low...

Pushbroom scanning is a technique used in remote sensing and imaging systems, particularly in satellite and aerial sensors, to capture images of the Earth's surface or other objects. In pushbroom...

Pyramid error in optics refers to an aberration in the shape of an optical surface, particularly in the context of mirrors. It is a type of distortion that can occur when the surface of a mirror...

The figure of merit of a resonator, defined as (2p) x (average energy stored in the resonator)/(energy dissipated per cycle). The higher the reflectivity of the surfaces of an optical resonator, the...

Q-switched operation, or q-switching, is a technique used in lasers to produce short and intense pulses of light. The term "Q" in q-switching stands for "quality factor," which is a measure of the...

Quantitative phase imaging (QPI) is an advanced imaging technique used in microscopy to measure and analyze the optical phase information of transparent specimens. Unlike traditional brightfield...

The term quantum refers to the fundamental unit or discrete amount of a physical quantity involved in interactions at the atomic and subatomic scales. It originates from quantum theory, a branch of...

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 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...

Quantum key distribution (QKD) is a method of secure communication that utilizes principles from quantum mechanics to establish a shared secret key between two parties, typically referred to as Alice...

Quantum sensing refers to a class of sensing technologies that leverage principles from quantum mechanics to enhance the precision and sensitivity of measurements. Traditional sensors operate based...

Quantum-enhanced metrology refers to the use of quantum mechanics principles and techniques to enhance the precision and sensitivity of measurements in metrology—the science of measurement....

A qubit, short for quantum bit, is the fundamental unit of information in quantum computing and quantum information processing. Unlike classical bits, which can exist in one of two states (0 or 1),...

In gradient index optics, a gradient profile in which the index varies in a direction perpendicular to the optical axis. Radial gradient lenses can focus light even when the lens surfaces are flat,...

Ratio of the radiance of the specimen to that of a perfect reflecting or transmitting diffuser identically irradiated.

The radiant flux per unit area emitted from a surface.

The force exerted on a surface by radiation.

An eyepiece consisting of two planoconvex lenses of the same focal length, with facing convex surfaces.