Institute of Modern Optics, Nankai University, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Tianjin 300350, China.
School of Materials Science and Engineering, Nankai University, Tianjin 300350, China.
Nanoscale. 2023 Apr 27;15(16):7566-7576. doi: 10.1039/d2nr05737a.
As a Dirac material, an allotrope of graphene, namely γ-graphyne (γ-GY), is proved to have excellent nonlinear optical properties. Unfortunately, the saturable absorption properties and ultrafast photonics applications of γ-GY at the 1.5 μm band, which play vital roles in optical communication, have not been reported so far. Herein, γ-GY nanosheets (NSs) are prepared by an improved mechanochemical method, and a saturable absorber (SA) is fabricated by a laser-induced deposition method. The modulation depth (MD) and saturable fluence at 1.5 μm are found to be 5.40% and 23.46 μJ cm, respectively. Consequently, by inserting the as-prepared SA into an Er-doped fiber laser (EDFL), Q-switching and mode-locking operation with high stability are realized. Also, the mode-locking pulses are verified to be polarization-locked vector solitons (PLVSs) based on further study. With increasing pump power, the phase difference between the two orthogonal components increases, leading to the evolution of state of polarization (SOP). Additionally, the degrees of polarization (DOPs) are measured and all reach more than 97%, meaning high polarization stability. Therefore, this work not only broadens the application scope of γ-GY in ultrafast photonics, but also provides an important foundation for the study of soliton dynamics.
作为狄拉克材料，石墨烯的同素异形体，即 γ-石墨炔（γ-GY），被证明具有优异的非线性光学性能。遗憾的是，γ-GY 在 1.5μm 波段的饱和吸收特性和超快光子学应用，在光学通信中起着至关重要的作用，迄今为止尚未有报道。在此，通过改进的机械化学方法制备了 γ-GY 纳米片（NSs），并通过激光诱导沉积法制备了饱和吸收体（SA）。在 1.5μm 处，调制深度（MD）和饱和光强分别为 5.40%和 23.46μJ/cm。因此，通过将制备的 SA 插入掺铒光纤激光器（EDFL）中，可以实现高稳定性的 Q 开关和锁模操作。此外，进一步研究验证了锁模脉冲是偏振锁定矢量孤子（PLVS）。随着泵浦功率的增加，两个正交分量之间的相位差增加，导致偏振状态（SOP）发生演化。此外，还测量了偏振度（DOP），所有 DOP 都达到了 97%以上，表明偏振稳定性很高。因此，这项工作不仅拓宽了 γ-GY 在超快光子学中的应用范围，而且为孤子动力学的研究提供了重要基础。
