Design and analysis of fiber coupling system for laser diode stacks

The fiber coupling system for semiconductor laser diode stacks was simulated by Zemax. Fiber coupling system based on twenty-eight mini-bars in two stack arrays as laser sources is advantageous to reduce costs and improve coupling efficiency. Output beam could be focused into the fiber of 600 μm core diameter with 0.22 numerical aperture by collimating, combining and focusing. The output power of more than 1500 W and the coupling efficiency of more than 93 % is realizable. Importantly, the factors of alignment errors of fiber and optical elements which impact on coupling efficiency are analysed.