Generating a geometric structure light field from a digital laser by specifying a laser cavity phase boundary with a Gaussian-convoluted target field.

This research proposed a simple method to design the projected phase boundary of the SLM (spatial light modulator) of the digital laser for the generation of a structure light field of geometric shape. In the proposed method, the phase boundary of the digital laser was designed to match the convolution field of the specified geometric structure field and Gaussian field instead of matching the specified geometric structure field. The phase boundary design suppressed the light reflected from the SLM of a high-inclination angle that is difficult to achieve stable oscillation in the laser resonator. Using the proposed phase boundary design, the laser output with energy distribution closed to geometric structures such as a quadrangular pyramid, triangular pyramid, cone, and multi-ring was produced through experiments. The geometric structure light field generated in this research will be beneficial to the related applications of photolithography and photopolymerization for making micro-elements.