针对光学微腔调制解调系统中存在的纹波噪声进行了理论分析,得出了纹波噪声来源于分立光学器件接头之间形成的F-P谐振腔结构。对光纤F-P腔的特性进行了分析得到了F-P腔透射光传递函数;对F-P腔的谐振特性进行了仿真得到了不同端面反射率下的谐振特性曲线,并分析了反射率与精细度的关系以及反射率对谐振特性的影响。提出了两种抑制纹波噪声的方法,即端面反射抑制方法和相位调制抑制方法,实验结果表明,两者有效地抑制了系统中的纹波噪声,提高了谐振信号的信噪比,为解调信号的获得和光学微腔的谐振点跟踪锁定奠定了基础。
The ripple noise comes from the FP resonator structure formed in the joint between discrete optics according to the theoretical analysis for the presence of it in the modulation and demodulation system. According to the analysis of the fiber FP cavity characteristics, transmittance function of the FP cavity is obtained. Its resonance characteristics were simulated and the resonance characteristic curves were obtained under different facets with different reflectivity. The relationship between the reflectivity and the finesse, and the influence of the reflectivity on the characteristics of the resonant are obtained. The two methods to suppress the ripple noise are proposed, the facet reflection method and the phase modulation suppression method. The result of the experiment shows that both methods suppress the ripple noise in the system effectively, improve the signal-to-noise ratio of the resonant signal, and lay the foundation to obtain the demodulated signal and track the optical micro-cavity resonance point.