Research on 2 μm polarization maintaining laser cavity based on the depolarization characteristics of a corner cube prism

Abstract

Based on the Jones matrix theory, a polarization maintaining 2 μm ring laser with a cavity structure of corner cube prisms (CCPs) is firstly presented in this paper. The changes of polarization state are simulated and coincide with the corresponding 2.06 μm experimental results for output beams after the CCP. Research results show that if the incident beam is circularly polarized or linearly polarized, the output beam will be generally elliptically polarized. Only when the polarization azimuths of linearly polarized incident beams are 16.06°, 43.94°, 46.06° and 73.94° can the linearly polarized output beams with different polarization azimuth angles be obtained. As such an incident beam passes through two CCPs arranged in the same way according to four specially reflection sequences (ACB and BCA, BCA and ACB, BAC and CAB, CAB and BAC) respectively, the polarization maintaining 2 μm laser can be realized. This work provides a reference basis for the design of a 2 μm corner cube ring cavity laser to realize the preservation of polarization state, which have practical significance to improve the output characteristics of 2 μm laser.