Development of optically addressed liquid crystal light valve for high power density beam control

As a beam control device, optically addressed liquid crystal light valve is easy to produce thermal effect due to absorption under the action of high-power density laser, resulting in damage to photoconductive materials, conductive films and liquid crystals. At the same time, thermal effect will also affect the uniformity of the device, reduce the extinction performance of the device. These factors limit the application of the device in laser processing, high power density laser shaping and other fields. To solve the application limitation of optically addressed liquid crystal light valve in the field of high power density beam control, an optically addressed liquid crystal light valve for high power density laser system is developed. The on/off ratio of the light valve is not less than 140∶1. It can work normally in the continuous laser system higher than 2300 W/cm². At the same time, the light valve can work normally in the femtosecond pulse laser system with high repetition frequency gigawatt power density. Under the action of the maximum power density laser of the system, the light valve has no obvious temperature change. The maximum average power density of the pulse system exceeds 300 W/cm².