Focal Plane Array (FPA)

The so-called Focal Plane array (FPA) is a special type of bolometer and is used as a thermal detector in infrared cameras. The FPA is based on a series of small thin-film bolometers arranged in a matrix in the focal plane of the detector. This results in a planar pixel sensor, allowing an improved price-performance ratio in various applications.

Vanadium oxide (VOX) and amorphous silicon alternative technologies are used as the materials for the thin-film bolometers required. Typical detector sizes today are 160×120, 320×240 and 640×480 pixels. Whilst in the past pixels were generally 35×35 µm in size, these days pixel sizes of 25×25 µm, 17×17 µm or even 12×12 µm are possible. Among other things, the resulting reduction of the detector surface size also results in smaller and lower cost optical systems.