Mei Yongli, Wang D N, Wang Qiaoben, Zhang Yan
Opt Lett. 2024 Aug 15;49(16):4609-4612. doi: 10.1364/OL.528812.
Whispering gallery mode (WGM) resonators are usually discrete optical devices, which have integration difficulties with an optical fiber system. Here we present a new, to the best of our knowledge, type of optical fiber whispering gallery mode resonator based on a cylindrical cavity, which is located in the multimode fiber core and fabricated by femtosecond laser micromachining together with fast hydrofluoric acid etching techniques. When light traveling in the fiber core is tangent to the cylindrical cavity wall, it is coupled into the cavity and circulates along the cavity wall to excite WGM resonance before being coupled out to the same tangential path and continuing propagation in the fiber core. The device is fully integrated into the optical fiber, simple in fabrication, convenient in operation, low in cost, and has a good quality factor (Q) of 1.06 × 10. The device enriches the family of WGM resonators and is expected to have promising applications in photonics.
回音壁模式（WGM）谐振器通常是分立的光学器件，与光纤系统存在集成困难。据我们所知，在此我们提出一种新型的基于圆柱形腔的光纤回音壁模式谐振器，该圆柱形腔位于多模光纤纤芯中，通过飞秒激光微加工结合快速氢氟酸蚀刻技术制造而成。当在光纤纤芯中传播的光与圆柱形腔壁相切时，它会耦合到腔内，并沿腔壁循环以激发WGM谐振，然后再耦合回相同的切向路径并继续在光纤纤芯中传播。该器件完全集成到光纤中，制造简单，操作方便，成本低，并且具有1.06×10的良好品质因数（Q）。该器件丰富了WGM谐振器家族，有望在光子学领域有广阔的应用前景。
