A Hybrid Simulated Annealing Approach for Loaded Phase Optimization in Digital Lasers for Structured Light Generation

This study proposes a method for designing spatial light modulator (SLM) projection phases in digital lasers using a simulated annealing (SA) approach combined with an initialized pre-designed phase to generate structured laser beams. SLM projection phases are optimized within the SA framework using a cost function based on the correlation between the corresponding laser field patterns and the target field. Numerical simulations demonstrate both the effectiveness of the proposed phase design method and its improvement in generating three geometric beams—quadrangular pyramid, triangular pyramid, and multi-ring fields—particularly with regard to enhanced edge sharpness. The resulting structured beams, especially those with simple geometric shapes, are suitable for microfabrication applications such as photolithography and photopolymerization. The proposed SA iteration framework is not limited to the L-shaped resonator used in this study and can be extended to digital laser cavities with higher numerical apertures, enabling the generation of more complex structured light fields.