In the field of optics, the Infrared spectral wavelength filter we often refer to is usually divided into three spectral bands: short wave infrared, medium wave infrared, and long wave infrared. Each infrared band has its own advantages and disadvantages, so corresponding filter usage bands are also developed based on their respective application scenarios.
Short wave infrared filter (wavelength approximately 1μm~3μm) It can generate clear images because, like visible light, light is reflected, absorbed, and scattered by objects, resulting in high contrast and resolution. Image sensors that can handle shortwave infrared light are often more expensive. Therefore, applications of filters based on shortwave infrared are usually concentrated in high value-added fields, such as anti-counterfeiting, process quality control, medical imaging, and semiconductor manufacturing.
Medium wave infrared filter (wavelength approximately 3 μ m~5 μ m) It is an ideal light source for measuring temperature changes and can avoid atmospheric scattering. Filter devices for medium wave infrared often require internal cooling, making them expensive. Medium wave infrared devices are applied in some important fields, such as national defense (identifying the exhaust of fighter jets) and industrial thermal imaging filter applications.
Long wave infrared filter (wavelength approximately 8 μ m~14 μ m) It has a wide range of applications, especially in the field of civil safety. Long wave infrared camera filters are mainly used for high-precision measurement of surface temperature of objects. In distant or very dark places, the filter of the long wave infrared phase can only detect thermal radiation by filtering out stray light. The image resolution of longwave infrared cameras is not high, but they can still meet the requirements of some applications, such as building inspection, thermal imaging monitoring, personal night vision, firefighter search and rescue, and other low-cost non cooling systems.
Previously, most infrared system filters were generally only used in military and industrial fields. The application of infrared imaging systems has gradually expanded to other fields. Infrared systems have great market prospects in civil safety equipment (non-contact infrared thermometers are used worldwide to prevent and control COVID-19), commercial consumer products, non-contact infrared thermometers and other applications.
