Three-dimensional holographic laser reconstruction and processing with optimized computer-generated hologram

We proposed a method that completes the three-dimensional holographic laser reconstruction and processing by using an optimized computer-generated hologram (CGH). A pm-designed CGH that contains three-dimensional (3D) information displayed on a liquid-crystal-on-silicon spatial light modulator (LCOS-SLM) can obtain the desired 3D diffraction pattern in the optical system, called 3D holographic laser reconstruction, and when it is reduced by an objective lens and incident on a sample, it can realize the 3D holographic laser processing. However, the imperfections including static imperfections and dynamic imperfections, such as inherent aberrations and external disturbances, that exist in the actual laser system will deteriorate the quality of the reconstruction and processing result. To compensate for the imperfections, a method that optimizes the CGH in the laser system was developed, called in-system optimization, and by using the optimized CGH, high-quality reconstructions and processing can be obtained, especially reflected on the uniformity of the 3D diffraction peaks and the consistency of the processed holes' scale. In this case, a 3D holographic laser reconstruction of 13 diffraction peaks at different focal planes with high uniformity of more than 95% was obtained, due to the CGH was optimized according to the resultant intensity measurement by the imperfections in the system. And the scale consistency variation of the corresponding processing holes proved the feasibility and significance of the CGH optimization. We believe this method can be applied to high-quality, high-efficiency, and high-precision 3D laser applications for industrial uses in the future.