Conversion Gaussian mode in the axial-symmetric light beam of different types with a ring interferometer

In this paper the method was suggested for conversion of the fundamental Gaussian mode into three types of axial-symmetric light beams: with reduced expansion, hollow and homogeneous intensity distribution. The mode conversion is based on the reflection of a part of laser beam under mismatched coupling conditions into the bow-tie ring cavity. It was established by the numerical modeling that transition between the laser beam types occurs as the reflection of interferometer mirror is changing. Calculated efficiency of the conversion method is amount 80%.