Liu Junting, Yang Fang, Lu Junpeng, Ye Shuai, Guo Haowen, Nie Hongkun, Zhang Jialin, He Jingliang, Zhang Baitao, Ni Zhenhua
State Key Laboratory of Crystal Materials, Institute of Novel Semiconductors, Shandong University, 250100, Jinan, Shandong, China.
School of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing, 211189, China.
Nat Commun. 2022 Jul 5;13(1):3855. doi: 10.1038/s41467-022-31606-8.
Atomically thin BiOSe has emerged as a novel two-dimensional (2D) material with an ultrabroadband nonlinear optical response, high carrier mobility and excellent air stability, showing great potential for the realization of optical modulators. Here, we demonstrate a femtosecond solid-state laser at 1.0 µm with BiOSe nanoplates as a saturable absorber (SA). Upon further defect regulation in 2D BiOSe, the average power of the mode-locked laser is improved from 421 mW to 665 mW, while the pulse width is decreased from 587 fs to 266 fs. Moderate Ar plasma treatments are employed to precisely regulate the O and Se defect states in BiOSe nanoplates. Nondegenerate pump-probe measurements show that defect engineering effectively accelerates the trapping rate and defect-assisted Auger recombination rate of photocarriers. The saturation intensity is improved from 3.6 ± 0.2 to 12.8 ± 0.6 MW cm after the optimized defect regulation. The enhanced saturable absorption and ultrafast carrier lifetime endow the high-performance mode-locked laser with both large output power and short pulse duration.
原子级厚度的BiOSe已成为一种新型二维（2D）材料，具有超宽带非线性光学响应、高载流子迁移率和出色的空气稳定性，在实现光调制器方面显示出巨大潜力。在此，我们展示了一种以BiOSe纳米片作为可饱和吸收体（SA）的1.0 µm飞秒固态激光器。在对二维BiOSe进行进一步的缺陷调控后，锁模激光器的平均功率从421 mW提高到665 mW，而脉冲宽度从587 fs减小到266 fs。采用适度的氩等离子体处理来精确调控BiOSe纳米片中的O和Se缺陷态。非简并泵浦-探测测量表明，缺陷工程有效地加速了光载流子的俘获速率和缺陷辅助俄歇复合速率。经过优化的缺陷调控后，饱和强度从3.6±0.2提高到12.8±0.6 MW cm 。增强的可饱和吸收和超快载流子寿命赋予了高性能锁模激光器高输出功率和短脉冲持续时间。
