基于拉锥光纤优化的光纤环镜滤波器特性研究

为了将拉锥光纤的光学特性和光纤环镜的滤波特性相结合,提出了一种用拉锥光纤优化的光纤环镜滤波器结构.实验研究发现,在级联的2阶高双折射光纤环镜滤波器中接入拉锥光纤,滤波器输出谱的主峰3dB带宽得到显著压缩,品质因数进一步提高,其Q值很容易达到5.2,滤波器在10dB~35dB调制深度范围内调谐更灵活,输出波形更加稳定.结果表明,该结构改善了高双折射光纤环镜滤波器特性,使调谐更为灵活.

Study on characteristics of fiber loop mirror filters based on tapered fiber optimization

Combining the optical properties of tapered fiber with the filtering characteristics of fiber loop mirrors, an optical loop mirror filter structure was put forward based on tapered fiber optimization. The study shows that after adding tapered fiber into cascaded second-order high-birefringence fiber (HBF) loop mirrors, 3dB bandwidth of main peak of filter output spectrum is significantly compressed. Quality factor is further improved and can reach about 5.2 easily. The study also shows that after adding tapered fiber into cascaded second-order HBF loop mirrors, tuning is more flexible in the modulation depth range from 10dB to 35dB and the output waveform becomes more stable. The filtering characteristics of HBF loop mirror were improved, and the filter is tunable more flexibly.