Infrared detector

An infrared detector converts infrared radiation into a measurable electrical signal. Detectors work through thermal changes or direct interactions between photons and charge carriers.

Photoconductivity: A material’s electrical conductivity changes when absorbed photons create or release charge carriers. Photon detectors use this effect to turn infrared absorption into a change in electrical current.
Infrared: Electromagnetic radiation with wavelengths longer than visible light and shorter than microwaves. Its wavelength determines which detector materials and optical components can respond.
Infrared thermography: Imaging that maps surface temperatures from emitted infrared radiation. Thermal cameras use detector arrays to turn infrared emission into temperature images.
Thermal detector: A radiation detector that senses energy through the temperature change it causes. Thermal detectors rely on heating, unlike photon detectors that respond directly to absorbed photons.
Thermoelectric effect: A temperature difference across a material produces an electrical voltage. Some thermal detectors read radiation-induced heating as a voltage.
Blackbody radiation: Electromagnetic radiation emitted by an object because of its temperature. Thermal detectors commonly measure infrared energy emitted by warm objects.
Night vision: Technologies that improve visibility in low-light conditions or using infrared radiation. Infrared detectors enable imaging beyond the visible-light sensitivity of unaided eyes.
Photon detector: A detector that converts absorbed photons directly into electrical charge or a voltage change. Photon detectors are often faster and more sensitive, but may require cooling.
Bolometer: A thermal radiation detector that measures heating through a change in electrical resistance. It is a common thermal detector design, especially in uncooled imaging systems.
Band gap: The energy difference between the valence and conduction bands in a solid. Photon detector materials need suitable band gaps to absorb infrared photons.

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