Photonics Dictionary: P

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...

A device using a parametric amplifier inside a resonant optical cavity to generate a frequency-tunable coherent beam of light from an intense laser beam of fixed frequency. This device is tuned by...

Present in photocurrent burst, it is the low frequency pulse that corresponds to the light scattered from the beams in the absence of heterodyne mixing.

In astronomy, the main lobe of an antenna pattern that has a small angular extent in two mutually perpendicular directions. Invisible in space, it would resemble a searchlight beam.

In optics and photolithography, a phase mask refers to a device that modifies the phase of light waves passing through it. The phase mask is used to control the spatial distribution of the light's...

Phase matching is a crucial concept in the field of optics, particularly in nonlinear optics and the generation of coherent light. It refers to the condition where the phases of two or more waves,...

A technique used to generate a phase shift between reference and sample light beams. The phase shift can be performed through the use of a mirror that is moved along the optic axis by a piezoelectric...

A chemical substance that exhibits fluorescence when excited by ultraviolet radiation, x-rays or an electron beam. The amount of visible light is proportional to the amount of excitation energy. If...

Periodic interruptions of a light beam incident on an absorbing medium that produce heat, expansion and acoustic wave generation. Since the amplitude of this wave is proportional to the absorbed...

An optical medical instrument that uses an intense, precisely focused beam of light to stop weakened blood vessels from hemorrhaging. The thermal effect of the beam strengthens the weakened vessels...

A device used to count objects that pass a given point by allowing each object to obstruct a beam of light falling on a photocell. Slow counting rates can be recorded by a mechanical counter, but...

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...

Spectroscopy used to study the concentration, diffusion and Brownian motion of small particles suspended in a fluid by measuring dynamic fluctuations of light that is scattered or fluoresced by the...

A photon jet is a narrow, highly collimated beam of light that is formed when light interacts with small dielectric microstructures, such as microspheres or microcylinders. This phenomenon arises due...

The recording achieved when a surface, illuminated by a signal-controlled light beam, emits electrons or reacts in some manner.

A document-transmitting process that uses a cylinder that rotates the document to be scanned and detected by a photoelectric cell. The cell transforms the light into electrical energy that may be...

A light beam whose electric vectors all vibrate in a single fixed plane.

A stationary noise that occurs for visible light photodetection when a steady light source, such as a heterodyne reference beam or high background light, dominates the signal.

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 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...

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...

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...