Analysis of the caustics of partially coherently combined truncated Gaussian beams

A theoretical model of the caustics of partially coherently combined beams (CBCs) was derived to model CBCs in the case of truncated Gaussian beams. The model enables the analysis of different lattice structures and partial coherence effects, including incoherent beam combining. The impacts of the coherence state, geometry of the array and truncation losses were analyzed. An optimal truncation level of about 6% was found and a maximum CBC efficiency of 62% was determined for this CBC system. With an increase in the beam numbers in the lattice, the relative caustics length decreases, which is consistent with the general rules of diffraction theory.