Research on the Phase Modulation Capability of Pure Phase Optical Addressing Space Light Modulator

This study provides a comprehensive investigation into the thermal effects and resolution constraints of a pure phase optical addressing spatial light modulator (PASLM) constructed on a liquid crystal light valve (OALV). Through thermal conduction modeling and numerical simulations, it was revealed that the BSO layer, owing to its high optical absorption and poor thermal conductivity, serves as the principal site of heat accumulation. Experimental measurements indicate that the PASLM achieves an effective resolution of 2.64 lp/mm, corresponding to an equivalent pixel size of approximately 189.4 μm. Temperature-dependent measurements demonstrate that as the device surface approaches its clearing point, the phase modulation depth precipitously decreases from 0.82λ to nearly zero, ultimately leading to device failure. To mitigate the attenuation of phase modulation depth induced by temperature rise, this work proposes two thermal management strategies: air cooling and water cooling. Simulation results reveal that both approaches substantially enhance heat dissipation, with water cooling exhibiting superior efficacy. Future efforts will focus on experimental validation to further improve the stability and resolution of the modulator under high-power laser irradiation.