CuCrO2 nanoparticles-polyimide films as saturable absorber for improving the output characteristics of passively Q-switched in ytterbium doped fiber lasers

CuCrO2 (CCO) Nanoparticles (NPs)-Polyimide (PI) films are successfully used to achieve passively Q-switched pulse output in ytterbium-doped fiber lasers (YDFL). The laser output characteristics can be regulated by using our as-fabricated CCO NPs-PI films at 1.03 μm. The pulse duration and repetition rate are simultaneously compressed by tens of times, at the same time single pulse energy and peak power are increased by one and three orders of magnitude, respectively. In particular, this is the first time that pulse duration and repetition rate are compressing simultaneously in YDFL. In addition, CCO NPs is integrated into YDFL for the first time. The reason for these phenomenons is that reverse saturable absorption reasonably increases the cavity loss, which effectively improves the modulation depth, over threshold degree and the accumulation of inversion particles. All these can prove that CCO NPs can be used as an important SA to construct high-performance Q-switched fiber laser.