HYPERSPECTRAL RUGATE DISPERSIVE ELEMENTS

Rugate Interference filters are ideally suited to hyperspectral applications due to their ability to combine multiple functions and spectral regions in a single element, their flexible design and manufacture techniques, and their superior performance. Rugate transmission notches can be placed virtually anywhere in the spectrum without the harmonic bands associated with conventional discrete filters. The bandwidth of the notch is easily controlled as is the inband transmission or optical density. The same holds true for pass band filters. Multiple notches or passbands (or a combination) are easily fabricated. We propose to design rugate elements specifically for hyperspectral imagers, evaluate their predicted performance on focal plane arrays, and fabricate a Phase I prototype with selected materials.