Alq <sub/>3</sub> saturable absorber for generating Q‐switched pulses in erbium‐doped fiber laser

摘要： Q-switch pulses were successfully produced utilizing an organic saturable absorber (SA) to modulate loss inside an erbium-doped fiber laser (EDFL) cavity. The organic material was tris-(8-hydroxyquinoline) aluminum (Alq3) and it was mixed with polyvinyl alcohol to form a film. The Q-switched EDFL operated at 1564.1 nm and the generated pulses were stable with tunable repetition rates. The repetition rates increased from 45.87 to 68.03 kHz as the pump power was elevated from 42.8 to 84.0 mW. Within this power range, the maximum pulse energy and the shortest pulse width were obtained at 139 nJ and 6.03 μs, respectively. The fundamental frequency of the electrical spectrum has a signal-to-noise ratio of 64 dB and thus verifies the stability of the laser. The results indicate that the proposed Alq3 material is feasible for use as SA in realizing a reliably stable and flexible Q-switch laser for 1.5 μm operation.