Photonics Dictionary: P

The branch of science that treats light as a wave phenomenon wherein light propagation is studied by wavefronts rather than rays, as in geometric optics.

The study of highly ionized gases. Many phenomena not exhibited by uncharged gases are associated with plasma physics.

A concave mirror that has the form of a paraboloid of revolution. The paraboloidal mirror may have only a portion of a paraboloidal surface through which the axis does not pass, and is known as an...

Particle acceleration refers to the process by which charged particles, such as electrons or protons, gain kinetic energy and increase their velocity. This acceleration can occur in various natural...

A phase-modulated sensor is a type of sensor that uses modulation of the phase of a signal to measure changes in a physical quantity. In such sensors, variations in the phase of the signal are...

A type of matched filter that responds only to the phase of incoming light; the output has a much greater intensity than that of a classical matched filter, which responds to phase and amplitude. The...

In biology, particularly genetics and evolutionary biology, the phenotype refers to the observable characteristics or traits of an organism, resulting from the interaction of its genetic makeup...

A phonon is a quantum of vibrational energy associated with the periodic motion of atoms or molecules in a crystalline lattice. In simpler terms, phonons are quanta of lattice vibrations in a solid...

A light therapy that utilizes nonionizing light sources, including lasers, LEDs, and broadband light, in the visible and infrared spectrum. It is a nonthermal process involving endogenous...

Photocathodes are specialized materials or surfaces that exhibit the photoelectric effect, wherein the absorption of photons leads to the emission of electrons. When photons with sufficient energy...

A spectroscopic process that detects and analyzes the discharge from an extrinsic surface with less than bandgap light. This method may determine the extrinsic surface-state energy levels of a...

Photogrammetry is a technique used to obtain accurate three-dimensional measurements of objects and environments through the analysis of photographs or imagery. It involves extracting information...

Photolithography is a key process in the manufacturing of semiconductor devices, integrated circuits, and microelectromechanical systems (MEMS). It is a photomechanical process used to transfer...

Photoluminescence is a phenomenon in which a material absorbs photons (light) at one wavelength and then re-emits photons at a longer wavelength. This process occurs when electrons in the material...

A photomask, also known simply as a mask or reticle, is a key component in the photolithography process used in semiconductor manufacturing and other areas of microfabrication. It is a high-precision...

Photometry is the branch of science that deals with the measurement of light, particularly in terms of its intensity and the way the human eye perceives it. It involves the quantification of visible...

A photomultiplier tube (PMT) is a highly sensitive vacuum tube that detects and amplifies low levels of light. It is widely used in various applications where high sensitivity, fast response times,...

A photonic integrated circuit (PIC) is a compact and integrated device that incorporates multiple photonic components and functions on a single chip, similar to the way electronic integrated circuits...

Photoplethysmography (PPG) is a non-invasive optical technique used to detect changes in blood volume in tissues. It measures variations in light absorption caused by the pulsatile nature of blood...

Photoresist is a light-sensitive material used in photolithography processes, particularly in the fabrication of semiconductor devices, integrated circuits, and microelectromechanical systems (MEMS)....

Photovoltaic (PV) refers to a technology that converts sunlight directly into electricity using semiconductors. The term "photovoltaic" is derived from the words "photo," meaning light, and...

Piezoelectric motion systems are mechanical systems that utilize piezoelectric materials to generate controlled motion or displacement. Piezoelectric materials exhibit the piezoelectric effect, which...

Piezoresistance is a phenomenon in materials science and physics where the electrical resistance of a material changes in response to applied mechanical stress or strain. This change in resistance...

A PIN photodiode is a type of photodetector or semiconductor device used to convert light signals into electrical signals. The name "PIN" is derived from the arrangement of the three semiconductor...

A plasma accelerator is a type of particle accelerator that uses electric fields and magnetic fields to accelerate charged particles, typically electrons or ions, by exploiting the motion of charged...

A Pockels cell, also known as an electro-optic modulator, is an optical device used to control the polarization of light by applying an electric field. It is named after the physicist Friedrich Carl...

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...

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 polymerase chain reaction (PCR) is a widely used molecular biology technique used to amplify a specific segment of DNA (deoxyribonucleic acid) through a series of temperature-controlled cycles....

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...

An accurately produced hole of any size and shape that is used as a masking device in an optical system. Pinhole apertures of accurate diameters often are produced by laser beam penetration or by...

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

Also referred to as primary color, this is the classic chromatic aberration of a single element caused by the variation of index of refraction as a function of wavelength.

Fluorescence produced as a result of the intrinsic property of the material itself or the doping of the material with trace elements.