US Patent 11249289 Spectral imager and spectral imaging method

A spectral imager includes a filter array, a pixel array, and a lenslet array therebetween. The filter array includes a plurality of filter regions. The lenslet array includes a plurality of lenslets each configured to form a respective image of the filter array on a respective one of a plurality of regions of the pixel array. The spectral imager may also include a fore-optic lens, the filter array being located between the lenslet array and the fore-optic lens. The spectral imager may also include a fore-optic lens, the filter array being located between the lenslet array and the fore-optic lens. Each of the plurality of filter regions is configured to selectively transmit radiation based on wavelength and/or polarization.