平面环形谐振腔的腔长对品质因数的增强效应

Enhancement Effect of Cavity Length on Quality Factor in the Planar Ring Resonant Cavity

品质因数(Q)是光学谐振腔的重要参数,大尺寸的平面环形谐振腔有着更大的单圈损耗,却具有更高的Q值。针对这个问题,从光子寿命的角度对环形谐振腔耦合结构进行了建模分析与仿真,提出了用等效单位传输损耗参数来表征谐振腔的腔长与品质因数之间的关系。设计、加工了不同腔长(3.1,9.5,12.6和18.8 cm)的氧化硅光波导环形谐振腔,其中谐振腔的耦合系数保持不变,测试结果显示:随着谐振腔的腔长增加,谐振腔的等效单位传输损耗降低,Q值增大,与仿真结果相符。该结论为高Q值光波导谐振腔的研究提供了一种新的途径。

The quality factor （Q） is an important parameter of the optical resonant cavity, and the large-size planar ring resonant cavity has larger single-lap loss, but has higher Q value. To solve this problem, the modeling analysis and simulation of the coupling structure of the ring resonant cavity were carried out based on the photon lifetime. The relation between the cavity length and the quality factor was characterized by using the equivalent unit transmission loss parameters. The silica optical waveguide-type ring resonant cavities with different cavity lengths （3.1, 9.5, 12.6 and 18.8 cm） were designed and fabricated, in which the coupling coefficient of the resonant cavity was kept constant. The test results show that with the increase of the cavity length, the equivalent unit transmission loss of the resonant cavity decreases and the Q value increases, which are consistent with the simulation results. This conclusion provides a new approach for the study of the optical waveguide resonant cavity with high Q value.