Photonics Dictionary

An instrument for determining the temperature of a hot object by examining the color spectrum of the visible light it gives off and comparing it to the known temperature and wavelength spectrum of...

A laser having a lasing material that is a fluorescing organic dye. Depending on the dye used, it can produce emission in any part of the visible spectrum into the near-infrared and ultraviolet, and...

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...

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 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 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...

Having properties resembling those of light- waves; e.g., the propagation of waves in the television spectrum.

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.

Essentially, a hologram of a hologram, in which the first-generation hologram is masked with a narrow slit. During image reconstruction, the slit operates as the exit pupil in image space. The...

Raman spectroscopy is a technique used in analytical chemistry and physics to study vibrational, rotational, and other low-frequency modes in a system. Named after the Indian physicist Sir C.V. Raman...

That element of a spectrum line in scattered radiation having a frequency equal to that of the corresponding incident radiation, due to ordinary or Rayleigh scattering.

The displacement of spectrum lines, as determined by the increasing distance between, and the relative velocity of, the observer and a light source, causing the lines to move toward the red portion...

Reflectance spectroscopy is a technique used to analyze the reflective properties of materials across various wavelengths of the electromagnetic spectrum. By measuring the reflectance of light from a...

The optically pumped, solid-state laser that uses sapphire as the host lattice and chromium as the active ion. The emission takes place in the red portion of the spectrum.

Sapphire crystal refers to a transparent, single-crystal form of aluminum oxide (Al2O3) known as corundum. It is one of the hardest known materials, second only to diamond on the Mohs scale of...

Sapphire optical fiber is a type of optical fiber made from single-crystal sapphire, which is a form of aluminum oxide (Al2O3) that is highly transparent in the infrared region of the electromagnetic...

A sapphire window refers to a transparent optical component made from sapphire crystal. Sapphire is a single-crystal form of aluminum oxide (Al2O3) that is highly prized for its exceptional optical...

A spectroradiometer having a means to scan different regions of the light spectrum, providing simultaneous representations of amplitude vs. wavelength of the spectrum.

Self-phase modulation (SPM) is a nonlinear optical phenomenon that occurs when an intense laser beam passes through a medium, causing a change in the phase of the light due to its interaction with...

Three filters used in making a color print of a color negative, red, green and blue-violet, respectively. Each filter transmits about one-third of the visible spectrum onto the print.

Short wavelength infrared (SWIR) refers to the portion of the infrared spectrum that encompasses wavelengths roughly between 1,000 and 3,000 nanometers (nm). In the electromagnetic spectrum, infrared...

A silicon photodiode is a semiconductor device that converts light into an electrical current. It is a type of photodetector specifically designed for detecting and measuring light intensity. Silicon...