Compact Long-Wave Infrared Hyperspectral Imager with Monolithically Integrated Tunable Optical Filter

By implementing sparse sampling and compressive sensing signal recovery techniques, we propose to build a snapshot spectrally multiplexed hyperspectral imager that will deliver ~27 wavelength channels from 8-12 µm using a 3x3 unit cell in a pixelated array on a strained layer super lattice focal plane. The spectral resolution of the system will be 150nm, but because of the multiplexed throughput of the filter the signal-to-noise will be much higher, similar to that of a 450nm bandpass. Spatial resolution will be reduced by a factor of 3 from that of the native pixel count on the array, i.e. a 640 x 480 will have a spatial sampling of 213x160.  However in the broadband monochrome image, the native 640x480 resolution can be recovered. In this way spectral detections can be overlaid upon the higher resolution broadband image.  This is commonly done in spectral imagers.  In Phase 1 of this project, we will develop models to determine the signal to noise possible with the multipass filters, design the filter transmission curve, and simulate the signal with modeling.  We will also develop several candidate implementations for the camera, including SLS focal planes and digital processors.  We will then work with our sponsor to trade-off the advantages of each design for the intended purpose and arrive at a design to be developed in Phase 2.  Phase 2 will culminate with the detailed design, build, and delivery of a LWIR hyperspectral imager.