Laser damage resistance analysis of liquid crystal devices based on ITO or GaN transparent electrode

Abstract

In this paper, in order to provide theoretical support for the higher laser damage resistant Optically-Addressable liquid crystal Light Valve (OALV) technology research, the laser damage model of liquid crystal optical devices under high power laser is established, and the damage characteristics of optically addressed spatial light modulators based on Si-doped gallium nitride (GaN) electrode and based on indium tin oxide (ITO) electrode are researched. Their thermal distribution and thermal stress under high power laser are analyzed respectively. The results show that the laser damage threshold of liquid crystal device with ITO electrode is only 500 mJ/cm², and the GaN electrode is several times larger than the former under pulse laser irradiation, the electrode of both liquid crystal devices are damaged first. Under the irradiation of high average power laser, the liquid crystal device of ITO electrode will reach the clear point first because of the thermal deposition. However, in liquid crystal devices with GaN electrode, the temperature rise of liquid crystal is small and the temperature distribution is uniform. GaN electrode has better thermal stability than ITO electrode under cooling measures. This undoubtedly shows that liquid crystal optical devices with GaN electrode have a good development potential in high power laser systems.