Comparative research on different solutions of a high-performance thin-film polarizing beam splitter

In the process of fabricating an ultra-high precision thin-film polarizing beam splitter(PBS), which is the key element in a new kind of Y-shaped cavity dual-frequency laser, low production yield is a serious problem. Based on the robust design method by controlling sensitivity of optical films to production errors, response characteristics to production errors of different kinds of PBSs are comparatively studied. By experimental study of robust design, essential determinant of sensitivity of PBSs to production errors is found to be the physical requirement that the propagation angle should be larger than the critical angle of total reflection of the interface between the substrate and outer space. By fulfilling the physical requirement, optimum incidence angle has been found by repeated robust design on different incidence angles, and a high-performance thin-film PBS with low sensitivity to production errors has been designed. The coating structure of the obtained PBS is simple and it is easy to be batch manufactured, which will make a positive impact on fabrication, engineering and application of the new Y-shaped cavity dual-frequency laser.