A compact high-repetition-rate passively mode-locked resonator structure and fiber laser

Abstract

The application discloses a compact high-repetition-frequency passively mode-locked resonant cavity structure and a fiber laser. The resonant cavity comprises a first ferrule, a semiconductor saturable absorber mirror, a first sleeve, a graded-index lens, a second sleeve, a gain fiber, a second ferrule and a dielectric film. The semiconductor saturable absorber mirror is arranged on the end face of the first ferrule, the first ferrule is connected to one end of the graded-index lens through the first sleeve, the other end of the graded-index lens is connected to the second ferrule through the second sleeve, the dielectric film is arranged on the other end face of the second ferrule, and the gain fiber is located in the second ferrule. By arranging the graded-index lens between the gain fiber and the semiconductor saturable absorber mirror, direct contact between the semiconductor saturable absorber mirror and the end face of the fiber is avoided, good heat dissipation of the resonant cavity can be realized while high-repetition-frequency mode-locked pulse output is obtained, and damage of the fiber laser caused by long-time mode-locked operation is avoided.