Focal Plane Array

A focal plane array (FPA) is a sensor technology used in infrared cameras to detect infrared radiation and convert it into electronic signals to create thermal images. The FPA consists of a grid of infrared-sensitive detector elements arranged at the focal point of the camera’s optical system. Each element in the array corresponds to a pixel in the final image, capturing the infrared radiation emitted or reflected by objects in the scene.

When infrared radiation strikes the focal plane array, each pixel element generates an electrical signal proportional to the amount of infrared radiation it receives. These signals are then processed and converted into a thermal image, where different levels of infrared radiation are represented by various shades or colors, depicting temperature differences within the scene.

Focal plane arrays can be made from various materials sensitive to different infrared wavelength ranges, such as indium antimonide (InSb) for mid-wave infrared (MWIR) or vanadium oxide (VOx) and amorphous silicon (a-Si) for long-wave infrared (LWIR). The choice of material and the specific design of the FPA influence the infrared camera’s sensitivity, resolution, and spectral response.