Simple single-step coherent beam combination phase locking enabled by single-detector multifrequency heterodyne technique

Single-detector multifrequency heterodyne (SDMFH) phase control method, which can achieve simple single-step phase locking in coherent beam combining (CBC) applications, is proposed and comprehensively analyzed. Numerical results demonstrate that laser phases can be independently extracted in the frequency domain with high accuracy, enabling single-step phase locking of a large number of channels by the SDMFH method. Up to 100-channel CBC laser system has been demonstrated numerically to converge to a combining efficiency of 99.5% with 0.07 rad residual phase in a single step. The capability of locking a tiled-aperture array to arbitrary phase patterns in a single step is also verified. Comprehensive parameter analysis illustrates the design rules to avoid frequency overlap, and the performance under dynamic phase noise is investigated in comparison with the classical LOCSET technique. The proposed method offers a promising solution for large-scale, high-speed coherent beam combining.