Research progress on laser irradiation effect of liquid crystal phase control device of Shanghai Institute of Optics and Mechanics

[ Instrument Network Instrument Development ] Recently, Zhao Yuan'an, a researcher at the Thin Film Optics Laboratory of the Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, made new progress in the study of laser irradiation effects of liquid crystal optical phase-control devices, optimizing the design of liquid crystal optical phase-control devices. Practical guidance in high energy laser systems provides guidance. Related research results are published in [Optical Materials Express 9(2), 911-922 (2019,)], [Infrared Physics & Technology 99, 80-85 (2019)].

The liquid crystal optical phase control device has the advantages of high spatial resolution, compact structure, low power consumption, etc., and can realize precise adjustment of beam amplitude, wavefront, polarization and pointing, and is widely used in laser fusion, photoelectric countermeasure, laser radar, laser Communication and other fields. In recent years, the field of high-energy lasers has also put forward clear requirements for liquid crystal optical phase-control devices, but its laser load capability has constrained applications.

The research group innovatively developed the chromatographic experimental technique, and studied the energy deposition and conduction of liquid crystal optical phase-controlled devices under high peak power and high average power laser irradiation by adjusting transparent conductive electrode film (ITO) and orientation layer (PI). The physical mechanism of coupling between layers within the device. Experimental and theoretical simulations show that under the action of high peak power laser, the ITO layer instantaneously absorbs thousands of degrees of temperature rise and vaporizes, breaking the binding of the PI layer to form organic damage; under the action of high average power laser, the ITO layer The endothermic temperature rise is slow, and the temperature gradient inside the device is extremely small after heat conduction, but the clearing point temperature of the commonly used liquid crystal material is between 50 ° C and 100 ° C, and the liquid crystal molecules first fail. The above research provides important guidance for the design, regulation and practical application of liquid crystal optical phase control devices in high energy laser systems.

Relevant research has been supported by the National Natural Science Foundation of China, the National Key Laboratory of Applied Optics, and the Open Fund of the State Key Laboratory of Pulsed Power Laser Technology.