Bulk α-alumina embedded tapered fiber as Q-switcher in an erbium-doped fiber laser

We present bulk α -alumina (Al 2 O 3 ) in a polydimethylsiloxane matrix decorated tapered fiber as a Q-switcher for microsecond pulse generation. The integration of α -Al 2 O 3 -saturable absorber (SA) in an erbium-doped fiber laser yielded a Q-switched operating regime within 62.0–308.6 mW pump power. The shortest pulse width was 7 μ s, whereas the repetition rate was tunable from 19.17 to 43.24 kHz. This work reveals a substantial improvement over previously reported Al 2 O 3 -SA works with a recorded pulse energy of 150.32 nJ and an estimated damage threshold of beyond 6.75 GW cm −2 incident intensity. Our findings suggest that α -Al 2 O 3 -SA has enormous potential as a next generation light-absorbing material for high-energy photonic devices.