Performance Assessment and Optimization for Incoherent Laser Beam Combining Based on a Concave Blazed Grating
X. Fu, F. Wang, X-Y. Zhang, Z-S. Zhu, Z-F. Deng, Y-W. Ma and S-B. Zhan
For the incoherent beam combining system using a concave grating as beam combiner, the methods of the system performance assessment, as well as the grating mount optimization are presented. The system performance assessment reveals that the incoherent combining system can carry out the good spatial overlap results, but the radius of the combined beam in Z-direction is much larger than that in Y-direction due to non-uniform distribution of aberration. The optimization result of the grating mount indicates that the grating should be designed into the mount similar to parabolic, and the maximum aberration along the y-axis is less than 4 ´ 10-14 m-1 under the optimized mount structure.
Keywords: Yb-doped fibre laser, laser beam, concave grating, incoherent beam combining, intensity distribution, spatial overlap result, system optimization