Wang Chuanshuo, Gui Lili, Mei Xianglong, Chen Hao, Ding Fei, Meng Chao, Bozhevolnyi Sergey I, Xu Kun
Opt Express. 2024 Feb 12;32(4):6423-6431. doi: 10.1364/OE.515612.
Intracavity optical metasurfaces with compact and flexible light manipulation capabilities, effectively enrich the implementation of miniaturized and user-friendly orbital angular momentum (OAM) laser sources. Here we demonstrate a wavelength-tunable figure-9 Yb-doped vortex fiber laser solely with standard non-polarization-maintaining single-mode fibers, which utilizes a gap-surface plasmon (GSP) metasurface as the intracavity mode regulation component to generate OAM beams, extending the avenues and related applications for cost-effective OAM laser sources. Gained by the broadband operation range of the metasurface, the figure-9 fiber laser could emit OAM light with center wavelength tunable from 1020 nm to 1060 nm and of high mode purity (about 90%). OAM beams with different topological charges such as l = ±1 have been obtained by changing the metasurface design. The proposed fiber laser with the intracavity GSP metasurface provides a reliable and customized output of OAM beams at the laser source, holding great promise for a wide range of applications in optical communications, sensing, and super-resolution imaging.
具有紧凑且灵活的光操纵能力的腔内光学超表面，有效地丰富了小型化且用户友好的轨道角动量（OAM）激光源的实现方式。在此，我们展示了一种仅使用标准非保偏单模光纤的波长可调谐9字形掺镱涡旋光纤激光器，该激光器利用间隙表面等离子体（GSP）超表面作为腔内模式调节组件来产生OAM光束，拓展了经济高效的OAM激光源的途径及相关应用。得益于超表面的宽带工作范围，9字形光纤激光器能够发射中心波长在1020 nm至1060 nm之间可调且模式纯度高（约90%）的OAM光。通过改变超表面设计，已获得了不同拓扑电荷（如l = ±1）的OAM光束。所提出的带有腔内GSP超表面的光纤激光器在激光源处提供了可靠且可定制的OAM光束输出，在光通信、传感和超分辨率成像等广泛应用中具有巨大潜力。
