Research of Infrared Imaging at Atmospheric Pressure Using a Substrate-Free Focal Plane Array

An equivalent circuit model to the substrate-free focal plane array (FPA) is established. Using this fast and effective model, the performance of infrared (IR) imaging at atmospheric pressure is investigated and it is found that the substrate-free FPA has the ability of IR imaging at atmospheric pressure, whereas it has a slightly degraded noise equivalent temperature difference (NETD) as compared with IR imaging under a high vacuum. This feature is also identified experimentally by a substrate-free FPA with pixel size of 50×50 μm ². The NETDs are measured to be 160 mK at 10^?2 Pa pressure and 1.08 K at atmospheric pressure.