Structured light reconstruction by Computer-Generated hologram in defect state

The generation of structured light from Computer-Generated Hologram (CGH) using spatial light modulators (SLM) has a wide range of applications, but there is currently a lack of research on localized defects in SLM devices. Considering that the local damage of SLM can lead to hologram defect, its result can be equivalent to the process of normal hologram generated structured beam with its near field being blocked. In this paper, CGH loaded onto digital micromirror device (DMD) is used to generate structured beams, and two cases of local defect states at the center and edge of the DMD are discussed. The results show that the reconstructed light field obtained by central defect is quite similar to the original light field, while the reconstructed light field obtained by edge defect is a much similar to the lower case of the original light field. The article further demonstrates the reconstructed results in coherent superpositions of Hermite-Gaussian modes using DMD-generated structured beams based on the single mode regime. This study expands the application scenarios for the generation of structured light beams with SLM.