Next Generation Broadband Grating for Hyperspectral Thermal Infrared Imagers, Year 1

Design and electron-beam fabricate a shaped-groove concave/convex grating to significantly extend the wavelength range of future airborne and space-based HyTES-like (Hyperspectral Thermal Emission Spectrometer) systems. Grating wavelength range will be 3 µm to 12 µm (MWIR-LWIR). Current HyTES wavelength range is 7.5 µm to 12 µm (LWIR only). The shaped-groove design can produce tailored efficiency to equalize instrument SNR across full wavelength range (compensates for signal and detector responsivity variation with wavelength). Flat efficiency shaped-groove proof of concept design shown at right. Concave/convex grating will be electron-beam fabricated using improved writing schemes to improve uniformity reduce ghosts/scatter. Grating performance (efficiency and scatter) will be measured in a laboratory setup (FY 2015 end state). Grating performance will be demonstrated in a laboratory breadboard spectrometer with a JPL HOT-BIRD* detector (FY 2016 end state). More »