Burst-mode pulse generation in passively mode-locked all-fiber green/orange lasers at 543 nm and 602 nm

• Qiujun Ruan, Jinhai Zou, chunna feng, Tingting Chen, hang wang, zhipeng dong, and Zhengqian Luo
• received 01/31/2024; accepted 04/17/2024; posted 04/18/2024; Doc. ID 520141
• Abstract: We report on the experimental realization of, to the best of our knowledge, the first green and orange passively mode-locked all-fiber lasers. Stable mode-locking in the burst-pulse status is achieved at the wavelengths of 543.3 nm and 602.5 nm, respectively. The figure-9 cavity comprises the fiber end-facet mirror, gain fiber (Ho3+: ZBLAN fiber or Pr3+/Yb3+: ZBLAN fiber) and fiber loop mirror (FLM). The FLM with long 460 HP fiber is not only used as an output mirror, but also acts as a nonlinear optical loop mirror for initiating visible-wavelength mode-locking. The green/orange mode-locked fiber lasers with the fundamental repetition rates of 3.779/5.662 MHz produce long bursts containing ultrashort pulses with the 0.85/0.76 GHz intra-burst repetition rates, respectively. The ultrashort intra-burst pulses are stemmed from the dissipative four-wave-mixing effect in the highly nonlinear FLM as well as the intracavity Fabry-Perot filtering. Long bursts of 22.2/11.6 ns with ultrashort pulses of 87/62 ps are obtained in our experiment. The visible-wavelength passively mode-locked lasers in all-fiber configuration and burst-mode would represent an important step towards miniaturized ultrafast fiber laser and may contribute to the applications in ablation-cooling micromachining, bio-medicine imaging and scientific research.