Passively Q-switched erbium-doped fiber laser based on gold nanorods

We have demonstrated that the gold nanorods (GNRs) can be used as effective saturable absorbers for passively Q-switched erbium-doped fiber laser (EDFL). Two types of GNRs were synthesized by a seed-mediated growth method. The longitudinal surface plasmon resonance wavelengths of the GNRs with different aspect ratios were around 1068 and 1442 nm, respectively. The GNRs were mixed with sodium carboxymethylcellulose (NaCMC) to form GNRs-NaCMC films with different absorption wavelengths. Using these GNRs-NaCMC films, 9.6-μs pulses with a repetition rate of ∼22.9 kHz and 10.4-μs pulses with a repetition rate of ∼22.4 kHz were obtained from the passively Q-switched EDFLs at a pump power of ∼120 mW, respectively.