Passively high-power Q-switching in Er- and Er/Yb doped fiber with CdTe

Abstract

In this work, Cadmium Telluride (CdTe) thin-film was demonstrated as a saturable absorber (SA) to induce Q-switching in the erbium-doped fiber laser (EDFL) and erbium-ytterbium co-doped fiber laser (EYDFL) cavities. CdTe thin film was prepared by the liquid-phase exfoliation method and sandwiched between two fiber ferrules to complete the fiberized SA assembly. Firstly, the CdTe-SA was inserted into the EDFL cavity and stable Q-switched pulses were observed at a threshold pump power of 88mW. The shortest pulse width and the highest repetition rate measured for the EDFL cavity were 6.10 ± 0.02 μs and 42.3 ± 1.3 kHz respectively, at a maximum pump power of 295 mW. At a maximum pump power of 295 mW, the highest average output power produced by the Q-switched pulses in the EDFL cavity was 0.15 mW. Meanwhile, Q-switched pulses in the EYDFL cavity self-start at the threshold pump power of 1.4 W. The maximum repetition rate obtained was 99.5 ± 1.5 kHz and a pulse width of 2 μs at a maximum pump power of 3 W. At this pump power, the highest average output power produced by the Q-switched pulses in the EYDFL cavity was 70.0 ± 0.2 mW. This is the first demonstration of a high average power passively Q-switched fiber laser operating in the C-band employing EDF and EYDF as the gain medium and CdTe thin-film as SA that we are aware of.