Q switched fiber laser based on saturable absorption of ferroferric oxide nanopa

We demonstrate that ferroferric-oxide (Fe3O4) nanoparticles exhibit nonlinear saturable absorption property at 1.55 μm, and fabricate two filmy saturable absorbers by embedding the nanoparticles into a polyvinyl alcohol (PVA) film or polyimide (PI) film separately. In the Fe3O4-PVA (Fe3O4-PI) Q-swit