Gold nanoparticles film for Q-switched pulse generation in thulium doped fiber laser cavity

Passively Q-switched thulium doped fiber laser(TDFL)has been successfully demonstrated using gold nanoparticles(GNPs),which were embedded into polyvinyl alcohol as saturable absorber(SA).The stable self-starting Q-switched laser was generated to operate at 1891 nm when a tiny piece of the prepared film was slot in between two fiber ferrules and incorporated into the laser cavity.The repetition rate can be adjusted from 48.54 kHz to 49.64 kHz while the pulse width decreased from 3.52μs to 2.38μs with the increase of 1550 nm pump power from 840 m W to 930 m W.The corresponding pump power output power linearly increased from 3.62 m W to 6.3 m W with a slope efficiency of 2.53%.The maximum peak power and pulse energy were recorded at about 39 m W and 0.12μJ,respectively at pump power of 930 m W.The Q-switching operation was caused by the surface plasmon resonance absorption of GNPs.