Dielectric optical microcavities have been explored as an excellent platform to manipulate the light flow and investigate non‐Hermitian physics in open optical systems. For whispering gallery mode optical microcavities, modifying the rotational symmetry is highly desirable for intriguing phenomena such as degenerated chiral modes and directional light emission. However, for the state‐of‐the‐art approaches, namely deforming the cavity geometry by precision lithography or introducing local scatterers near the cavity boundary via micromanipulation, there is a lack of flexibility in fine‐adjusting of chiral symmetry and far‐field emission direction. Here, precise engineering of cavity boundary using electron‐beam‐induced deposition is reported based on rolled‐up nanomembrane‐enabled spiral‐shaped microcavities. The deformation of outer boundary results in delicate tailoring of asymmetric backscattering between the outer and inner rolling edges, and hence deterministically strong mode chirality. Besides, the crescent‐shaped high‐index nanocap leads to modified light tunneling channels and inflected far‐field emission angle. It is envisioned that such a localized deposition‐assisted technique for adjusting the structural deformation of 3D optical microcavities will be highly useful for understanding rich insights in non‐Hermitian photonics and unfolding exotic properties on lasing, sensing, and cavity quantum electrodynamics.

中文翻译：

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通过腔几何形状的后转向控制方向性发光和模式手性

介电光学微腔已被探索为在开放光学系统中操纵光流和研究非赫米特物理学的绝佳平台。对于耳语的画廊模式光学微腔，对于引起诸如退化的手性模式和定向发光之类的有趣现象，非常需要改变旋转对称性。但是，对于最先进的方法，即通过精密光刻使腔体几何形状变形或通过微操作在腔体边界附近引入局部散射体，在微调手性对称性和远场发射方面缺乏灵活性方向。在此，据报道基于卷起的纳米膜驱动的螺旋形微腔，利用电子束诱导沉积对腔边界进行了精确设计。外边界的变形导致外滚动边缘和内滚动边缘之间不对称反向散射的精细调整，因此确定性强的模式手征性。此外，新月形的高折射率纳米帽会导致改进的光隧穿通道并改变远场发射角。可以预见的是，这种用于调节3D光学微腔结构变形的局部沉积辅助技术，对于理解非厄密光子学中的丰富见解以及在激射，传感和腔量子电动力学方面展现出奇异的特性将非常有用。新月形的高折射率纳米帽导致修改后的光隧穿通道和弯曲的远场发射角。可以预见的是，这种用于调节3D光学微腔结构变形的局部沉积辅助技术，对于理解非厄密光子学中的丰富见解以及在激射，传感和腔量子电动力学方面展现出奇异的特性将非常有用。新月形的高折射率纳米帽导致修改后的光隧穿通道和弯曲的远场发射角。可以预见的是，这种用于调节3D光学微腔结构变形的局部沉积辅助技术，对于理解非厄密光子学中的丰富见解以及在激射，传感和腔量子电动力学方面展现出奇异的特性将非常有用。