A method to adjust the focusing and coherence characteristics of laser beam complexly using a liquid crystal spatial light modulator

In this paper, a method to adjust the focusing and coherence characteristics at the same time based on liquid crystal spatial light modulator (LC SLM) was proposed. The theory of adjusting the focusing and coherence characteristics of laser beam with a LC SLM is studied in detail. Expressions for beam size and the radius of curvature of the output partially coherent beam from the LC SLM are obtained from the cross-spectral density function. The experiment shows that, by using a LC SLM, we provided a convenient and practical method to adjust the focusing and coherence characteristics of laser beam, and it also made the partially coherent beam coordinate with other optical system to meet different application needs.