Chen Longlong, Huang Jing, Li Ning, Zhu Hao, Hu Jianbang, Miao Lili, Zhao Chujun
Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China.
Nanophotonics. 2022 Apr 27;11(12):2931-2938. doi: 10.1515/nanoph-2022-0142. eCollection 2022 Jun.
Broadband pulsed lasers have become an indispensable part in optical communications, biomedical engineering, materials processing, and national defense. Inspired by the broadband and ultrafast optical components, great efforts from the laser and material community have been paid to explore the emerging nonlinear optical materials. Here, we found that the VO/VO core-shell heterostructures with type-II staggered band alignment exhibit broadband nonlinear optical response towards mid-infrared spectral range. The nonlinear optical characterizations verify that the heterostructures show the modulation depth and saturation intensity of 27% and 42 GW/cm at 1064 nm, 23% and 78 GW/cm at 1550 nm, and 16.5% and 63.9 GW/cm at 2800 nm, respectively. With the nonlinear optical modulator, stable mode-locked Yb-doped and Er-doped fiber lasers have been realized with pulse output as short as 310 ps and 633 fs, respectively. In addition, the stable Q-switched Er-doped fluoride fiber laser has been demonstrated with a pulse repetition rate of 89 kHz and the shortest pulse width of 680 ns, respectively. The experimental results indicate that VO/VO core-shell heterostructures can be broadband nonlinear optical modulators from the near-infrared to the mid-infrared spectral range, offering opportunities to develop high-performance photonic devices.
宽带脉冲激光器已成为光通信、生物医学工程、材料加工和国防领域不可或缺的一部分。受宽带和超快光学元件的启发，激光和材料领域的研究人员付出了巨大努力来探索新型非线性光学材料。在此，我们发现具有II型交错能带排列的VO/VO核壳异质结构对中红外光谱范围表现出宽带非线性光学响应。非线性光学表征证实，该异质结构在1064nm处的调制深度和饱和强度分别为27%和42GW/cm，在1550nm处为23%和78GW/cm，在2800nm处为16.5%和63.9GW/cm。利用该非线性光学调制器，分别实现了脉冲输出短至310ps的稳定锁模掺镱光纤激光器和633fs的掺铒光纤激光器。此外，还展示了稳定的调Q掺铒氟化物光纤激光器，其脉冲重复频率为89kHz，最短脉冲宽度为680ns。实验结果表明，VO/VO核壳异质结构可作为从近红外到中红外光谱范围的宽带非线性光学调制器，为开发高性能光子器件提供了机会。
