回音壁模式晶体腔凭借其高品质因数和小模式体积, 在光学滤波、非线性转换、光学传感等研究领域都具有重要的应用前景, 然而裸露光学微腔的谐振特性极易受外界环境干扰的影响, 针对基于氟化镁晶体回音壁模式微腔的光纤耦合封装技术进行了研究。通过氢氧焰熔融拉锥的方式制备了锥形光纤, 其锥腰直径约为2 μm。搭建了回音壁微腔与锥形光纤耦合测试实验平台, 优化后的锥形光纤耦合系统使回音壁模式晶体腔在一定波长范围内工作在少模状态, 品质因数达到5.15×107。此外, 完成了具有精准温控的耦合器件封装, 提升了锥形光纤和回音壁腔耦合系统的稳定性。从实际应用的角度出发, 为超高品质因数的回音壁模式晶体腔的封装提供了一种有益的尝试。

The whispering gallery mode(WGM) crystal cavity with a high quality factor and small mode volume has an important application prospect in the fields of optical filters, nonlinear converters, optical sensors and so on. However, the resonant characteristics of exposed optical microcavities are easily influenced by the external environment. In this paper, the coupling and packaging technology of the tapered fiber and the WGM micro-cavity based on the magnesium fluoride crystal is studied. The tapered fiber is prepared by oxyhydrogen flame, and the diameter of the taper waist is about 2 μm. An experimental platform for testing the coupling quality between micro-cavity and tapered fiber is set up. Only a few modes in a specific wavelength range are observed in the optimized the fiber coupling system, and the quality factor reaches 5.15×107. Furthermore, a coupling and packaging system with accurate temperature control is built to improve the stability of the coupling system. A useful idea is provided and realized for packaging ultra-high quality WGM crystal cavities from the perspective of practical application.