Technology of hyperspectral full polarization imaging based on superachromatic 1/4 wave plate and acousto-optic tunable filter

The measurement accuracy of spectropolarimetric imaging is severely affected by ambient temperature, voltage, and incident angle based on acousto-optic tunable filter(AOTF) and liquid crystal variable retarder(LCVR). The spectropolarimetric imaging system is more complex. However, the superachromatic wave plate has the advantage that the retardation varies very little with temperature and wavelength. According to it, a new method of full polarization hyperspectral imaging based on superachromatic wave plate and acousto-optic tunable filter was proposed. The working principle of the method was analyzed in detail. According to the slight fluctuation of retardation and the fast axis of the superachromatic 1/4 wave plate, the effect of this fluctuation on the polarization measurement was analyzed in detail. For these errors, a correction strategy was proposed. The specific principle of all the Stokes parameters images and the modified measurement verification experiment were performed for 633 nm waveband. The experiment result shows that the measurement error of the polarization degree of the system is less than 1% in the band of 450-950 nm, and the measurement deviation of the polarization orientation is less than 1.8. The experimental results show that the new technology principle is correct and the correcting strategy is feasible. This research can provide new theory and implementation scheme for high-precision, high-resolution, full-polarization imaging technology under complex conditions.