Long Hui, Liu Shunxiang, Wen Qiao, Yuan Huiyu, Tang Chun Yin, Qu Junle, Ma Sainan, Qarony Wayesh, Zeng Long Hui, Tsang Yuen Hong
The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, People's Republic of China. School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou, People's Republic of China.
Nanotechnology. 2019 Nov 15;30(46):465704. doi: 10.1088/1361-6528/ab33d2. Epub 2019 Jul 19.
Indium selenide (InSe) has attracted tremendous attention due to its favorable electronic features, broad tunable bandgap, high stability and other attractive properties. However, its further applications for nonlinear optics have not yet been fully explored. In this work, we demonstrate that few-layer α-InSe nanosheets exhibit strong saturable absorption properties over a wide wavelength range covering 800, 1064 and 1550 nm. The few-layer α-InSe nanosheets used for this experiment are fabricated via a simple ultrasonic exfoliation in liquid. Stable ultrafast mode-locking laser pulses are obtained from both ytterbium-doped and erbium-doped fiber laser systems operating at 1064 and 1550 nm, respectively. A pulse duration as short as 215 fs was achieved in the Er-doped fiber laser system. Stable output pulses over 6 h of operation were obtained in both laser systems. The pulse energy and peak power of the laser output pulses were increased by reducing the InSe thickness. These results indicate that α-InSe nanosheets with low layer numbers are promising candidates for broad ultrafast photonics devices, such as optical switchers, Q-switchers and mode lockers.
硒化铟（InSe）因其良好的电子特性、宽可调带隙、高稳定性和其他吸引人的性质而备受关注。然而，其在非线性光学方面的进一步应用尚未得到充分探索。在这项工作中，我们证明了少层α-InSe纳米片在覆盖800、1064和1550 nm的宽波长范围内表现出强饱和吸收特性。用于本实验的少层α-InSe纳米片是通过在液体中简单的超声剥离制备的。分别在工作于1064和1550 nm的掺镱和掺铒光纤激光系统中获得了稳定的超快锁模激光脉冲。在掺铒光纤激光系统中实现了短至215 fs的脉冲持续时间。在两个激光系统中均获得了超过6小时运行的稳定输出脉冲。通过减小InSe的厚度提高了激光输出脉冲的脉冲能量和峰值功率。这些结果表明，低层数的α-InSe纳米片是用于诸如光开关、Q开关和锁模器等广泛的超快光子器件的有前途的候选材料。
