Ren Long-Fei, Si Zhi-Zeng, Liu Jing, Sun Hao, Dai Chao-Qing, Sun Huai-Jun, Wang Yue-Yue
College of Optical, Mechanical and Electrical Engineering, Zhejiang A&F University, Lin'an 311300, China.
Jiyang College of Zhejiang A&F University, Zhuji 311800, China.
ACS Appl Mater Interfaces. 2025 Jan 15;17(2):3785-3795. doi: 10.1021/acsami.4c18533. Epub 2025 Jan 1.
As a member of the chalcogenide family, NiSe exhibits a direct bandgap of 1.74 eV, making it a promising candidate for nonlinear optical devices. However, its potential in the near-infrared region of the telecommunication band has not been fully explored. In this study, a well-coupled saturable absorber (SA) device is fabricated for the first time using NiSe nanosheets, and it is applied to an ultrafast fiber laser, achieving an ultrashort pulse laser output with an optical conversion efficiency of 13.9%. The laser based on NiSe SA achieves tunable multisoliton mode locking, including conventional solitons, bound-state solitons, dual-wavelength solitons, and second to fourth harmonic solitons, over a wavelength range of 1528.5-1556 nm by adjusting the resonator's polarization state through the polarization controller and controlling the pump power. Numerical simulations and soliton dynamic analysis in the study of NiSe SA reveal the intricate details and behaviors of ultrafast soliton pulse locking. The results indicate that the well-coupled NiSe SA, characterized by a modulation depth of 36.73%, a saturation intensity of 0.287 MW/cm, and excellent spectral broadband absorption properties, can enhance intracavity nonlinear effects and enable the realization of stable and tunable multisoliton mode-locked pulses. Additionally, soliton collisions with group velocity differences are investigated under stable dual-wavelength soliton output, especially vector dual-wavelength soliton. This demonstrates the excellent application potential of NiSe SA in fields such as ultrafast optical communications and information encryption.
作为硫族化物家族的一员，硒化镍具有1.74电子伏特的直接带隙，这使其成为非线性光学器件的一个有潜力的候选材料。然而，其在电信波段近红外区域的潜力尚未得到充分探索。在本研究中，首次使用硒化镍纳米片制造了一种耦合良好的饱和吸收体（SA）器件，并将其应用于超快光纤激光器，实现了光转换效率为13.9%的超短脉冲激光输出。基于硒化镍SA的激光器通过偏振控制器调整谐振器的偏振态并控制泵浦功率，在1528.5 - 1556纳米的波长范围内实现了可调谐的多孤子锁模，包括传统孤子、束缚态孤子、双波长孤子以及二至四阶谐波孤子。对硒化镍SA的数值模拟和孤子动力学分析揭示了超快孤子脉冲锁模的复杂细节和行为。结果表明，耦合良好的硒化镍SA具有36.73%的调制深度、0.287兆瓦/平方厘米的饱和强度以及优异的光谱宽带吸收特性，能够增强腔内非线性效应并实现稳定且可调谐的多孤子锁模脉冲。此外，在稳定的双波长孤子输出下，特别是矢量双波长孤子，研究了具有群速度差的孤子碰撞。这证明了硒化镍SA在超快光通信和信息加密等领域具有优异的应用潜力。
