Photonics Dictionary

A device for detecting visual and infrared radiation using a photoconductor as the principle sensing element.

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,...

An infrared detector in which radiation passes through a doped germanium crystal, creating a voltage drop that can be measured in terms of incident intensity.

Any of the many devices used to detect the presence of radiation from a specific region of the electromagnetic spectrum.

Also known as radiation thermometer. A pyrometer in which the radiant intensity from the source to be measured is used to calculate its temperature. The usual detector is a thermocouple, thermopile...

A scintillation crystal, also known simply as a scintillator, is a material that emits light when it interacts with ionizing radiation such as gamma rays, x-rays, or charged particles. The emitted...

A scintillation detector is a radiation detection device that utilizes scintillation crystals to detect and measure ionizing radiation, such as gamma rays, x-rays, or charged particles. It consists...

In a radiation detector, the ratio of the output to the input signal.

1. A generic term for detector. 2. A complete optical/mechanical/electronic system that contains some form of radiation detector.

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...

Measure of a detector's signal during exposure to radiation of a constant power level and varying wavelength.

A kind of spectrograph in which some form of detector, other than a photographic film, is used to measure the distribution of radiation in a particular wavelength region.

A terahertz spectrometer is a scientific instrument used to measure and analyze the properties of materials in the terahertz frequency range, typically spanning from about 0.1 to 10 terahertz (THz),...

Terahertz (THz) refers to a unit of frequency in the electromagnetic spectrum, denoting waves with frequencies between 0.1 and 10 terahertz. One terahertz is equivalent to one trillion hertz, or...

The instrument used to collect thermal radiation information on an object by scanning. It consists basically of a detector, a photoconductive element that converts incident radiation to an electrical...

A mechanical, electrical, thermal or optical detector designed to identify and measure ultrasonic radiation.

A device that serves to detect the presence of vacuum ultraviolet radiation. It may be photographic film, a thermopile, ion chamber, vacuum photodiode, photomultiplier or channel electron multiplier.

One of various types of fluorescent screens used to detect x-ray radiation. Photographic film is mildly sensitive to x-rays, but much more sensitive to light. Hence, in photographing x-ray...