Photonics Dictionary: P

A filtering method that restores a blurred image by setting its power spectrum equal to that of the original image.

The first-order spectrum formed by a diffraction grating.

The spectrum formed by a dispersing prism or a dispersing prism system.

Color sensitivity extended to cover the entire visible spectrum out to the red.

An array of lines in the infrared region of the emission spectrum of atomic hydrogen. Their wave numbers are expressed by the equation: where represents the wave number in the reciprocal centimeters,...

A form of dispersing prism, often used in monochromators, that consists of a common right-angle prism with a 30° dispersing prism attached to each of its square faces. The spectrum formed by the...

Phase distortion refers to a change in the phase relationships between different frequency components of a signal. In the context of signal processing, it occurs when the phase response of a system...

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...

A chemical compound that exhibits a reversible change in its absorption spectrum upon irradiation with given wavelengths of light.

Photochromic refers to a property exhibited by certain materials, typically organic compounds or dyes, which undergo reversible changes in color when exposed to light. Specifically, photochromic...

The reversible change in the absorption spectrum of certain compounds upon irradiation with a given wavelength of light.

The measurement and analysis of color using a photoelectric instrument having three filters with broad spectrum bands.

A form of photometric measurement, often used with light sources that are transparent or fluctuating, in which a photographic plate is used to obtain a record of a source's relative intensities over...

A technique used for noncontact inspection of semiconductor wafers. The material is illuminated by an excitation source that stimulates photoluminescence; the resulting spectrum is analyzed, yielding...

Photosynthetically active radiation (PAR) is the 400- to 700-nm region (visible light) of the electromagnetic spectrum that is absorbed and used by the plant for photosynthesis. Also referred to as...

Phototherapy is a medical treatment that involves the use of light to treat various conditions, particularly those related to the skin or mood disorders. There are different types of phototherapies,...

A broadband, visible picosecond probe pulse capable of measuring an entire absorption spectrum in one shot.

A transmission or reflecting grating with a flat or plane surface requiring a lens or concave mirror to focus the spectrum.

Optical fiber channel characterization scheme based on three assumptions; the discrete mode spectrum can be replaced by a continuum; the loss due to coupling between guided and radiation modes...

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...