As one of the main technologies of military night vision equipment, infrared imaging device and its system technology have been developed since the 1980s. Countries such as the US, UK, France, Germany and Russia are leading the way in research, development and application. Its equipment includes infrared observer, infrared sight, periscope infrared thermal imager, fire control thermal imager, infrared tracking system, forward-looking infrared system and infrared camera. The scope of application of these devices are:

Army: night reconnaissance, surveillance, aiming and firing, guidance and air defense, etc.; Navy: surveillance, patrol, observation and missile tracking, etc.;

Air Force: navigation, search, tracking, identification, capture, observation and fire control of reconnaissance aircraft, attack aircraft, bombers and helicopters;

Aerospace: reconnaissance, surveillance and photography of spaceborne systems;

Civil: medical diagnosis, fire prevention and rescue, furnace temperature detection and high-voltage engineering, etc.

Infrared imaging technology is essentially a wavelength conversion technology, that is, a technology that converts infrared radiation into visible light, and uses the difference in the radiation of each part of the scene itself to obtain the details of the image. Usually two bands of 3~5um and 8~14um are used. This imaging technology not only overcomes the need for artificial infrared radiation sources for active infrared night vision devices, and thus brings about the shortcomings of easy self-exposure. It also overcomes the disadvantage that passive low-light night vision devices completely rely on ambient natural light. The infrared imaging system has a certain ability to penetrate smoke, fog, haze, snow and other restrictions and to identify camouflage. It is not blinded by strong light and flashes on the battlefield, and can achieve long-distance, all-weather observation. These features make thermal imaging systems particularly suitable for military applications.

Infrared imaging technology can be divided into two types: cooled and uncooled. The former is divided into the first generation, the second generation and the third generation, and the latter can be divided into two types: pyroelectric camera tube and pyroelectric detector array.