Scaling potential of beam-splitter-based coherent beam combination

The impact of nonlinear refraction and residual absorption on the achievable peak average power in beam-splitter-based coherent beam combination is analyzed theoretically. While remains limited only by aperture size, a fundamental limit given thermo-optical thermo-mechanical properties splitter material its coatings. Based our analysis, 100 kW can be obtained with state-of-the-art optics at maintained high quality (M2 {\leq} 1.1) 2% loss combining efficiency. This result indicates that power-scaling potential today's far from being depleted. A scaling route to megawatt-level discussed for optimized geometry.