Stable Q -Switched Erbium-Doped Fiber Laser Based on Topological Insulator Covered Microfiber

We demonstrated a stable passively Q-switched Er-doped fiber laser around the optical communication band with a microfiber-based topological insulator (TI) Bi2Te3saturable absorber. The saturable absorber was fabricated by the optical deposition method and its nonlinear transmission ~1568 nm was characterized. By virtue of the TI saturable absorber, stable Q-switched pulses can be formed with pulse repetition rate increasing from 2.6 to 12 kHz, and pulse duration decreasing from 50 μs to 9.5 μs through altering the pump strength. Our results evidently show the effectiveness of Bi2Te3-based saturable absorber and its potential applications for pulsed laser generation.