Simplified system for relative phase controlbetween two input beams for coherentpolarization beam combination

We devised a simplified system for coherent polarization beam combination (CPBC), in which two beams with orthogonal polarizations are combined with a polarizing beam splitter (PBS). In a CPBC system, control of the relative phase between two beams is important to obtain an output beam with stable polarization. Herein, the beam leaked from PBS is used to control the relative phase, realizing a robust system. We experimentally demonstrate that the proposed system can be operated with high efficiency and without quality deterioration.