Improvement in high-average-power laser resistance of an optically addressed spatial light modulator based on a new air-gap structure

This study reports a new optically addressed spatial light modulator (OASLM) structure based on bilateral-sapphire substrates with an air gap that exhibits high-average-power laser resistance. The resistance of traditional OASLMs to high-average-power laser irradiation is primarily affected by the high absorption of the transparent conductive film and low thermal conductivity of the substrate. Thermodynamic simulations indicated that the thermal conductivity of a sapphire substrate was significantly higher than that of K9 glass. Using sapphire as the substrate significantly reduced the temperature increase of indium tin oxide. An OASLM based on this structure, without any auxiliary cooling measures, exhibited a higher high-average-power laser resistance (170 W/cm2) than that of a K9 glass OASLM (9 W/cm2).