Q-switched fiber laser using a polysulfone membrane enhanced with biosynthesized zinc oxide and titanium dioxide nanoparticles for use as saturable absorber

We presented the polysulfone membrane enhanced with zinc oxide and titanium dioxide (Psf membrane ZnO TiO 2 ) saturable absorber (SA) to induce passively Q-switched erbium-doped fiber laser (EDFL). The Psf membrane ZnO TiO 2 was synthesized by the phase inversion technique. To obtain the Psf membrane ZnO TiO 2 as a SA, the SA was deposited on the fiber ferrule through a simple exfoliation technique. The modulation depth of the Psf membrane ZnO TiO 2 SA was 1.06%, with a saturation intensity of 0.0006 MW cm −2 . Stable Q-switched pulses were generated at 1572 nm with a threshold pump power of 59.80 mW after inserting the prepared Psf membrane ZnO TiO 2 into the EDFL ring cavity. As the pump power ranges from 59.80 mW to 165.50 mW, the repetition rate increases from 13.05 to 22.61 kHz, while the pulse duration decreases from 76.60 to 44.23 µ s. When the pump power reaches a maximum power of 165.50 mW, the corresponding pulse energy and optical signal-to-noise ratio are 19.00 nJ and 61.27 dB, respectively. To our best knowledge, this is the first research utilizing Psf membrane ZnO TiO 2 as SA to generate Q-switched pulses. Our research work addresses a new reference for the generation of pulsed laser using Psf membrane ZnO TiO 2 and discovers that it has numerous applications in nonlinear optics and ultrafast laser technology, which significantly broadens the barrier of materials for the ultrafast laser techniques.