Large angle range beam scanning control based on crystal spatial light modulator

In order to realize the laser scanning control within 90° cone angle, a beam deflection and angle amplification optical path system based on LCSLM (liquid crystal spatial light modulator) were researched and established by using the advantages of high precision and no mechanical inertia in beam deflection control. The programmable phase modulation algorithm and angle amplification optical path structure of spatial light modulator was proposed. The relations between the beam deflection angle of spatial light modulator and the phase gray scale driving diagram was derived, and the angle amplification optical path system with an angle magnification ratio higher than 22 times was designed. On this basis, the experimental system of beam scanning control was established, the angle emergence range of the device was measured, and the actual angle magnification ratio was compared with the designed value. The experimental results show that the emergence field angle of the developed system can reach to 91.22°, and the regular shape scanning within the range of emergence field angle by distortion correction can be realized. This research has important research value and application prospect in the fields of beam agile control, wireless laser communication, target search and tracking.