Optical nanofiber cavity research has mainly focused on the fundamental mode. Here, a Fabry–Pérot fiber cavity with an optical nanofiber supporting the higher-order modes (TE01${\mathrm{TE}}_{01}$, TM01${\mathrm{TM}}_{01}$, HEo21${\mathrm{HE}}_{21}^o$, and HEe21${\mathrm{HE}}_{21}^e$) is demonstrated. Using cavity spectroscopy, with mode imaging and analysis, we observed cavity resonances that exhibited complex, inhomogeneous states of polarization with topological features containing Stokes singularities such as C-points, Poincaré vortices, and L-lines. In situ tuning of the intracavity birefringence enabled the desired profile and polarization of the cavity mode to be obtained. We believe these findings open new research possibilities for cold atom manipulation and multimode cavity quantum electrodynamics using the evanescent fields of higher-order mode optical nanofibers.

中文翻译：

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使用具有高阶模式纳米光纤的法布里-珀罗光纤腔操纵偏振拓扑

光学纳米纤维腔的研究主要集中在基模上。在这里，演示了带有支持高阶模式（TE 01${\mathrm{TE}}_{01}$、TM 01${\mathrm{TM}}_{01}$、HE o 21${\mathrm{HE}}_{21}^o$和HE e 21 ）的光学纳米纤维的 Fabry-Pérot 光纤腔。${\mathrm{HE}}_{21}^e$使用腔光谱，通过模式成像和分析，我们观察到腔共振表现出复杂、不均匀的偏振态，其拓扑特征包含 Stokes 奇点，例如 C 点、Poincaré 涡流和 L 线。就地调谐腔内双折射能够获得所需的腔模式轮廓和偏振。我们相信这些发现为使用高阶模式光学纳米纤维的消逝场进行冷原子操纵和多模腔量子电动力学开辟了新的研究可能性。