Nanosecond $Q$ -Switched Erbium-Doped Fiber Laser With Wide Pulse-Repetition-Rate Range Based on Topological Insulator

We demonstrated the generation of stable topological insulator nanosecond Q -switched erbium-doped fiber laser with wide pulse repetition rate range. By virtue of the excellent saturable absorption property of the topological insulator saturable absorber, the Q -switched fiber laser with a section of high concentration erbium-doped fiber and two fiber Bragg gratings in a simple linear laser cavity can produce Q -switched pulse with a wide range of pulse repetition rate from 12.6 to 177.7 kHz, and minimum pulse duration of 217 ns. This laser configuration enables laser operation free of self-mode-locking effects.