Graphene nanoplatelets (GnP)-PVA based passive saturable absorber

We demonstrate a passive Q-switched at 1.5 μm region by integrating a graphene nanoplatelets (GnPs) embed in Polyvinyl Alcohol (PVA). The GnPs was dispersed with the aid of surfactant and mixed with PVA by solution casting aroach and then dried at ambient temperature to develop a GnPs-PVA film. The integration of the passive Q-switcher is by attaching a small portion of the developed GnPs-PVA film at the end of fiber ferrule in the laser cavity with ring configuration to generate pulse laser. The experimental works show that the proposed GnPs-PVA film based passive Q-switcher operates at input pump power ranges from 39 mW to 148 mW with central wavelength of 1530.76 nm. We observe the tunable repetition rate from 33 kHz to 91.5 kHz with the shortest pulse width of 2.42 μs. The laser produce maximum instantaneous output peak power and pulse energy of 1.2 mW and 5.9 nJ, with the recorded signal to noise ratio of 28 dB