Infrared detectors are photoelectric sensors that can respond to external infrared light radiation, and are currently one of the focus of the development of the sensor field. Detectors made with it are equipment needed for military, meteorology, agriculture, industry, medicine, etc. It involves basic sciences such as physics and materials and comprehensive science and technology in multidisciplinary fields such as optics, mechanics, microelectronics, and computers.
1. Photon detector
The working mechanism of the photon detector is to use the photon flow of the incident light radiation to interact with the electrons in the infrared detector material to change the energy state of the electrons and cause various electrical phenomena. This phenomenon is called the photon effect.
There are two types of photon detectors: internal photoelectric detector and external photodetector. The latter is divided into four types: photoconductive, photovoltaic, photoemission, and photomagnetoelectric.
2. Heat detector
The working principle of the infrared thermal detector is to use the radiant heat effect. The infrared detection device receives the radiation energy and causes the temperature to rise, and then the contact type temperature measuring element measures the temperature change, thereby outputting an electrical signal.
There are three main types of heat detectors: thermopile, pyroelectric type and gas type.