高双折射Sagnac环透射特性的理论与实验研究

Transmission characteristics of high-birefringence Sagnac loop filter

采用传输矩阵分析法、数值模拟和实验研究相结合的方法研究了由光耦合器(OC)、偏振控制器(PC)和保偏光纤(PMF)组成的高双折射Sagnac干涉环的透射特性。理论分析了PMF特性和PC状态对输出特性的影响,并通过数值模拟得到了PMF长度、双折射率(Δn)和PC状态不同时所对应的透射光谱。最后通过实验验证得出了波长间隔只由PMF的长度和双折射率Δn决定,透射率大小只由PC状态决定,而透射谱的峰值位置由PMF和PC状态共同决定的规律。实验结果与理论分析结果非常一致,对Sagnac环透射规律的研究对这种可调谐滤波器在多波长光纤激光器中的应用具有一定的参考价值。

Transmission characteristics of a high-birefringence Sagnac loop was studied by using transfer matrix method,numerical simulation and experimental investigation.The Sagnac loop filter was composed of an optical coupler（OC）,a polarization controller（PC） and polarization-maintaining fiber（PMF）.The influence of PMF characteristics and PC state on transmission characteristics of Sagnac loop was theoretically analyzed.The transmission spectra of different PMFs,birefringences（Δn） and PCs state were obtained through numerical simulation.The experiment was done and the results indicated that the wavelength spacing was determined by PMF length and birefringence（Δn）,the transitivity by PC state and transmission peak by PMF and PC state.The experimental results agreed with the theoretical analysis.