Generation of Q-switched and soliton mode-locked pulses with bismuth tellurite saturable absorber

We demonstrated Q-switched and soliton mode-locked pulses operating at 1569.51 nm and 1564.45 nm, respectively by using a newly developed Bismuth Telluride Polyvinyl Alcohol (Bi₂Te₃ PVA) film as saturable absorber (SA). By incorporating the SA into an Erbium-doped fiber laser (EDFL) cavity, Q-switched pulses were obtained within a pump power range from 101.90 to 175.82 mW. At the maximum pump power, the laser operated at repetition rate of 92.76 kHz and pulse width of 4.76 µs while producing the highest single pulse energy of 39.4 nJ. By incorporating an additional 200 m long single-mode fiber into the laser cavity, stable soliton mode-locked pulses were generated. It operated at repetition rate of 0.97 MHz with a pulse width of 2.97 ps and a signal-to-noise ratio (SNR) of 50.89 dB.