We demonstrate that ferroferric-oxide(Fe_3O_4) nanoparticles exhibit nonlinear saturable absorption property at1.55 μm, and fabricate two filmy saturable absorbers by embedding the nanoparticles into a polyvinyl alco...We demonstrate that ferroferric-oxide(Fe_3O_4) nanoparticles exhibit nonlinear saturable absorption property at1.55 μm, and fabricate two filmy saturable absorbers by embedding the nanoparticles into a polyvinyl alcohol(PVA) film or polyimide(PI) film separately. In the Fe_3O_4-PVA(Fe_3O_4-PI) Q-switched fiber laser, the pulse repetition rate increases from 8.5 kHz(5.5 kHz) to 28 kHz(49 kHz) and the pulse duration decreases from 23.5 μs(47 μs) to 6 μs(3.5 μs) by varying the pump power from 25 m W(23 mW) to 150 m W(650 mW). Experiment results indicate that PI-based saturable absorbers can afford larger powers than PVA-based saturable absorbers, which can be attributed to the higher fusion point of the PI film. The Fe_3O_4-PI saturable absorber exhibits features of high damage threshold, low cost, and good flexibility, which could be applied in fields of near-infrared pulse generation and frequency conversions.展开更多
基金National Natural Science Foundation of China(NSFC)(61575162,61405161,11404263,61675169)Natural Science Foundation of Shannxi Province(2015JQ6211)
文摘We demonstrate that ferroferric-oxide(Fe_3O_4) nanoparticles exhibit nonlinear saturable absorption property at1.55 μm, and fabricate two filmy saturable absorbers by embedding the nanoparticles into a polyvinyl alcohol(PVA) film or polyimide(PI) film separately. In the Fe_3O_4-PVA(Fe_3O_4-PI) Q-switched fiber laser, the pulse repetition rate increases from 8.5 kHz(5.5 kHz) to 28 kHz(49 kHz) and the pulse duration decreases from 23.5 μs(47 μs) to 6 μs(3.5 μs) by varying the pump power from 25 m W(23 mW) to 150 m W(650 mW). Experiment results indicate that PI-based saturable absorbers can afford larger powers than PVA-based saturable absorbers, which can be attributed to the higher fusion point of the PI film. The Fe_3O_4-PI saturable absorber exhibits features of high damage threshold, low cost, and good flexibility, which could be applied in fields of near-infrared pulse generation and frequency conversions.
