Infraredsensitive

Infraredsensitive describes the property of a device, material, or system that responds to infrared radiation. Infrared is the portion of the electromagnetic spectrum roughly from 0.75 micrometers to several hundred micrometers, commonly divided into near-, shortwave, midwave, and longwave bands. An infrared-sensitive sensor detects infrared radiation and converts it into an electrical signal or other measurable response.

Detection mechanisms vary by technology. Photodetectors use narrow-bandgap semiconductors such as indium antimonide (InSb), mercury cadmium telluride (HgCdTe), or indium gallium arsenide (InGaAs) to absorb IR photons and generate charge carriers. These detectors often require cooling to suppress dark current and noise. Bolometers and microbolometers measure changes in resistance caused by heating from absorbed IR radiation; they can operate at or near room temperature and are common in thermal imaging cameras. Pyroelectric detectors rely on temperature-dependent polarization to produce a signal from changing IR flux. Additional approaches include quantum well infrared photodetectors and various emerging materials like two-dimensional semiconductors.

Applications are wide and include thermal imaging for night vision, surveillance, industrial process monitoring, astronomy, environmental sensing, and IR spectroscopy. Performance is described by metrics such as spectral responsivity, detectivity (D*), noise-equivalent power (NEP), response time, and operating temperature. Practical design considerations include spectral range, cooling needs, noise characteristics, and environmental stability. Infraredsensitive technologies continue to evolve with goals of higher sensitivity, broader spectral coverage, faster response, and lower cost.