Bismuth telluride as a passive Q-switcher for neodymium-doped fiber laser

The scene of fiber laser has progressed very rapidly with the demonstration of various materials as saturable absorbers in a near- and mid-infrared laser cavity. However, the researchers focused on erbium-, ytterbium-, and thulium-doped fiber as a gain medium. Here, we proposed a neodymium-doped fiber laser setup to generate a Q-switched laser in a 1-μm regime. The laser utilized bismuth telluride, a topological insulator as a Q-switcher for pulse generation. With a linear absorption of approximately 5 dB at 1089 nm, this SA can generate a stable Q-switched laser in a neodymium-doped fiber laser cavity. It generates a stable Q-switched laser at 1089 nm when the pump intensity is adjusted between 167 and 190 mW. The pulsed laser owns the shortest pulse width of 6.48 μs with a maximum repetition rate of 40 kHz. The stability of the laser is promising since it has a signal-to-noise ratio of 40 dB. In the authors’ knowledge, this is the first demonstration of bismuth telluride as a saturable absorber in an all-fiberized neodymium-doped fiber laser cavity.