可用于传感领域的环形谐振腔游标效应的研究

为了验证光纤环形谐振腔的游标效应，对不同长度的光纤环形谐振腔进行了研究。实验研究了长度分别为2.24m和2.52m光纤环形谐振腔透射谱频率的对应关系，当谐振频率相同且自由频谱宽度个数差值为1时，根据差值等分测量原理，以其中一个谐振谱线作为标尺、另一个作为游尺，对标尺的自由频谱宽度九等分，得到游尺的最小测量分度为0.01GHz，这与MATLAB理论仿真结果一致。结果表明，通过改变谐振腔尺寸差，增加自由频谱宽度的等分刻度数，可以提高测量精度；基于微谐振腔对外界环境变化的敏感特性，谐振腔游标效应在高灵敏传感领域将具有潜在的应用。

Research of vernier effect of ring resonator in sensor fields

To verify the vernier effect of fiber ring resonators, fiber ring resonators in different length were studied. The relationship between the transmission spectrum and the fiber ring resonator with the length of 2.24m, 2.52m was analyzed and compared, one resonant spectrum could be used as the ruler and the other as the vernier, when the resonant frequency was the same and the number difference of free spectral range (FSR) was only one. Based on the difference aliquot measuring principle and by dividing FSR of the ruler into nine parts,the minimum measurement accuracy of the vernier was 0.01GHz which was consistent with MATLAB theoretical simulation result. Theory and experiments show that the accuracy can be improved by changing the size of the resonant cavity to increase the aliquot number of FSR difference. The vernier effect of resonator is expected to be potentially applied in the field of high-sensitivity sensor because of the sensitivity of the micro-cavity to the change of external environment.