Generalizing a quantum-well infrared single-pixel polarimeter (QWISPP) to Fourier transform spectral-polarimetric imaging

At previous SPIE meetings, we reported on an optoelectronic device that measures the complete polarization state of incident infrared light in a single pixel and in a single frame for a narrow wavelength band (δλ<0.05 μm). Using at least four quantum-well stacks and four linear gratings, each stacked alternating above the other, the device uses the interference among light paths to create a distinct pattern of photocurrents at each quantum-well stack coding for a specific polarization. In this paper, we will model the performance of this device, a quantum-well infrared single-pixel polarimeter (QWISPP), in the setting of a Fourier transform infrared (FTIR) imager. We model one column of QWISPP pixels detecting an inferferogram. Using an FTIR with randomly varying QWIsPP pixels to detect the interferogram, we discovered a technique that allows an 100x improvement in measured spectral-polarization uncertainty compared to the use of identical QWISPP pixels in an FTIR or grating spectrometer. The technique also enables a 15x improvement in the uniformity of the error across a sample spectrum. In other words, we turn into an advantage the imperfections in fabricating an FPA of QWISPPs.