Simulation of out-of-plane displacement measurement using vortex beam: on the base of liquid crystal spatial light modulator

In ESPI experiment, object beam and reference beam are always planar light. The plane light can be replaced by vortex beam. Vortex beams can be generated by a reflective liquid crystal spatial light modulator (LC-SLM) which added in the optical path. The generated vortex beam can be used as object light or reference light in out-of-plane displacement measurement. The out-of-plane displacement is simulated and analyzed before and after the object deformation. By phase shifting method and unwrapping, the distribution of phase difference is obtained. The simulation results demonstrate the efficacy of the proposed method for the out-of-plane displacement measurements.