Passive Q-switching of praseodymium (Pr 3+ )-doped fiber lasers at 635 nm with topological insulators (TIs) saturable absorbers (SAs) was experimentally demonstrated for the first time. TIs (Bi 2 Se 3 , Bi 2 Te 3 ) nanosheets were embedded in polyvinyl alcohol for film-forming and incorporated into a visible Pr 3+ -doped fiber laser cavity for Q-switching operation, respectively. The Bi 2 Se 3 -based Q-switched fiber laser has a wide range pulse-repetition-rate from 191.6 to 454.5 kHz, and the Bi 2 Te 3 one can be continuously tuned from 164.5 to 403.2 kHz. Both the Q-switching lasers have narrow pulse duration of nanosecond (ns)-level. Our results reveal that the TIs-based SAs are available for pulsed operation in the visible spectral range.Index Terms-Q-switched fiber laser, visible laser, topological insulator, pulse-repetition-rate.

No abstract

No abstract

In this paper, a compact Q-switched red (635.7nm) praseodymium (Pr 3+ )-doped fluorozirconate fiber laser using graphene-oxide (GO) as a saturable absorber (SA) is demonstrated experimentally. Furthermore, a silica fiber end coated with a dielectric film was employed to construct the compact resonator. The laser possesses a wide range of pulse repetition rate from 64.1 to 195.3 kHz and the minimum pulse duration of 554 ns. This is the first reported passively Q-switched laser, to the best of our knowledge, at visible region with a GO saturable absorber. The experimental results show that GO can be a promising SA for visible pulsed lasers.Index Terms-Visible laser, Q-switched fiber laser, graphene oxide, Pr-doped fiber laser.

No abstract