Imaging of gas leaks (especially of methane, but also of other gases) has traditionally been done with portable infrared cameras based on cooled InSb and QWIP FPAs. In these, either the FPA spectral response is tuned to the absorption wavelength of the gas of interest or a spectral filter is used in front of it. Alternatively, high-end spectrally selective (Fourier Transform Infrared – FTIR) cameras (also based on cooled FPAs) are used to detect gas leaks with high sensitivity, but at a price premium.
Now, a new generation of innovative uncooled gas sensors are being developed to not just monitor large gas leaks but also act as monitors for small leaks.
The effort in Japan to develop Type 2 Superlattice (T2SL) FPAs in Japan has taken a big step forward. Researchers at Sumitomo Electric, JAXA (Japan Aerospace Exploration Agency) and Ritsumeikan University have fabricated a 320 x 256/30 InAs/GaSb FPA with a 6 µm cutoff and an NETD of 31mK.
IRnova is developing megapixel T2SL (Type 2 Superlattice) FPAs to be used for imaging spectroscopy to detect various types of cancer. The aim is to develop both MWIR and LWIR FPAs with 1280 x 1024 format and 12 μm pixel pitch.
Active Protection Systems (APS) for armored vehicles are becoming a necessity as rocket propelled grenades (RPGs) and anti-armor munitions become more effective against even the best armor. In APS systems an incoming round is detected and tracked and a counter munition is fired to destroy the round before it can damage the vehicle.
In the most recent systems, infrared FPAs are being used.