A solid-state hyperspectral imager for real-time standoff explosives detection using shortwave infrared imaging

We present a new and innovative short-wave infrared (SWIR) hyperspectral imaging focal plane array (FPA) concept for bulk and trace standoff explosives detection. The proposed technology combines conventional uncooled InGaAs based SWIR imaging with the wavelength selectivity of a monolithically integrated solid-state Fabry-Perot interferometer. Each pixel of the array consists of a group of sub-pixels in which each sub-pixel is tuned to absorb a separate wavelength. The relative responses from the sub-pixels (i.e. wavelengths) are compared to the spectral characteristics of explosives in the SWIR to detect and locate them within an imaged scene among various background materials. The novel technology will be compact, and consume low power such that it can be used as a handheld device or mounted for persistent surveillance of crowded areas and checkpoints. The technology does not use any scanning nor tuning apparatuses such as MEMS devices, and is therefore fast, compact, lightweight and not susceptible to vibration. The technology is therefore ideal for man portable applications and unmanned vehicle platforms. An eyesafe (covert) illuminator may be used to provide illumination in situations when ambient light conditions are not sufficient. We will present a detailed design of the novel focal plane array and a theoretical standoff distance and false rates study.