Scaling potential of beam-splitter-based coherent beam combination
Michael Müller, Christopher Aleshire, Joachim Buldt, Henning Stark, Christian Grebing, Arno Klenke, Jens Limpert
Abstract
The impact of nonlinear refraction and residual absorption on the achievable peak- and average power in beam-splitter-based coherent beam combination is analyzed theoretically. While the peak power remains limited only by the aperture size, a fundamental average power limit is given by the thermo-optical and thermo-mechanical properties of the beam splitter material and its coatings. Based on our analysis, 100 kW average power can be obtained with state-of-the-art optics at maintained high beam quality (M 2 ≤ 1.1) and at only 2% loss of combining efficiency. This result indicates that the power-scaling potential of today’s beam-splitter-based coherent beam combination is far from being depleted. A potential scaling route to megawatt-level average power is discussed for optimized beam splitter geometry.