Qian-Qian Hao, Meng-Yu Zong, Zhen Zhang, Hao Huang, Feng Zhang, Jie Liu, Dan-Hua Liu, Liang-Bi Su, Han Zhang. Bismuth nanosheets based saturable-absorption passively Q-switching mid-infrared single-crystal fiber laser [J]. Acta Physica Sinica, 2020, 69(18): 184205-1