Performance of Reduced Polarimetric Optical Switching Demodulation Technique in Different Spatio-Temporal Polarization Modulation Schemes

The beam exchange is a classical supplementary technique for spatio-temporal modulation in a dual-beam setup. In order to save time, the reduced polarimetric-optical-switching (RPOS) technique was propsed as an alternative technique. In this work, we revisit the assumptions of several formulas specifically constructed for this technique and evaluate their validity in different modulation schemes (e.g., dependent modulation), especially when reference measurements are acquired using specific Stokes signals. Subsequently, we compare the RPOS technique based on the most appropriate formula with the demodulation method based on the demodulation matrix by using synthesized observation data. The artificial observation takes into account the influence several factors have on the modulated intensities, including dark current, gain variation, atmospheric seeing fluctuations, and photon noise. Our numerical tests demonstrate that the RPOS technique has an advantage in mitigating the effects of atmospheric seeing fluctuations and gain variations between two beams. However, the selection of a specific Stokes signal for reference measurements has a notable impact on performance in minimizing the effect of photon noise.