Infrared detectors are devices that sense infrared radiation, which is a type of electromagnetic radiation with wavelengths longer than visible light. They are commonly used in various applications, including thermal imaging, night vision, and temperature measurement. These detectors can identify heat emitted by objects, making them useful in fields like security, firefighting, and medical diagnostics. There are different types of infrared detectors, such as photoconductive, pyroelectric, and bolometric detectors. Each type operates based on different principles and materials, allowing them to detect infrared radiation in various conditions. Their ability to convert thermal energy into electrical signals enables the detection and analysis of heat patterns in the environment.