AOTF Based Spectro-Polarimetric Imaging System For Stand Off Chemical Detection

We propose an acousto-optic tunable filter (AOTF) spectropolarimetric imaging system for enhanced standoff chemical detection in the Long Wave Infrared (LWIR) wavelength region. The AOTF has no moving parts, making it a rugged and reliable device, and it provides polarimetric imaging capabilities, which enhances its chemical detection capabilities. We have been actively researching suitable materials for LWIR AOTF imaging systems for several years. All of our prior research on LWIR materials will be leveraged and utilized during the proposed work. We will optimize the device fabrication techniques that are needed to build the AOTF using mercurous halide materials. We will investigate the technique of apodization in the design of the AOTF device to reduce the detrimental effects of the sidelobes in the passband. The proposed spectral imaging system will have polarimetric imaging capabilities. Thus, the stand-off capabilities for chemical detection and tracking will be significantly enhanced from the polarization information. In Phase I of this work we will develop and design an AOTF spectral polarimetric imaging system that uses an LWIR focal plane array as the detector. The designed system will be fully built and demonstrated in Phase II of this project.