Tungsten Disulfide Film Based Saturable Absorber for Q-switched Pulses Generation

We have fabricated tungsten disulfide (WS2) film and use this as saturable absorber (SA) in Erbium-doped fiber laser (EDFL) cavity to generate Q-switched pulses train. The SA was obtained by mixing WS2 into PVA solution to form a composite film after drying process. A stable Q-switched pulses train operating at 1565.2 nm was successfully achieved by inserting the developed SA device into the EDFL cavity. The repetition rate of the laser can be tuned from 50.26 to 67.2 kHz as the pump power increased from 71.7 to 112.9 mW. At pump power of 112.9 mW, the maximum average output power of 1.94 mW, shortest pulse width of 1.92 us and maximum single pulse energy of 28.9 nJ were obtained. The generated pulses are consistent and stable, which useful in many practical applications.