AI 中文总结
本研究通过全光纤集成GaN基h-CBG腔实现共振增强SHG，显著提升信号强度，确立了将光学非线性纳入光纤光子系统的紧凑型可扩展方案。
AI 中文摘要
紧凑型且高效的光纤内频率转换对非线性和量子光子技术极具价值，但因非线性相互作用弱、光纤耦合效率有限，相关研究仍具挑战。本研究通过将氮化镓（GaN）孔型圆形布拉格光栅（h-CBG）腔直接转移至标准光纤，实现全光纤集成，展示了共振增强的二次谐波产生（SHG）。结合GaN的大二阶非线性极化率与宽光学透明窗口，所制备的GaN基h-CBG膜腔可实现强场限制与产生的SHG信号的垂直定向耦合输出。结果显示，与块状GaN及未图案化的独立GaN膜相比，该h-CBG器件的SHG信号显著增强。采用确定性拾取-放置转移技术，实现了GaN腔器件的稳定、精确光纤集成，可从传统光纤平台产生在线SHG。本研究为将光学非线性纳入基于光纤的光子系统提供了紧凑型、可扩展的方法。
英文摘要
Compact and efficient frequency conversion within optical fibers is highly desirable for nonlinear and quantum photonic technologies, yet it remains challenging due to weak nonlinear interactions and limited coupling efficiencies onto optical fibers. Here, we demonstrate resonantly enhanced second-harmonic generation (SHG) through the all-fiber integration of a gallium nitride (GaN) hole-type circular Bragg grating (h-CBG) cavity, directly transferred onto a standard optical fiber. Together with the large second-order nonlinear susceptibility and wide optical transparency window of GaN, the fabricated h-CBG membrane cavity on GaN enables strong field confinement and vertically directional out-coupling of the generated SHG signal. As a result, we observe drastically enhanced SHG signals from the h-CBG device compared with the bulk GaN and the unpatterned freestanding GaN membrane. Using a deterministic pick-and-place transfer technique, we demonstrate robust and precise fiber integration of the GaN cavity device, enabling in-line SHG generation from a conventional fiber platform. This work establishes a compact and scalable approach for incorporating optical nonlinearity into fiber-based photonic systems.
Comments19 pages, 5 figures
