Xu Xiaobin, Zhang Zuchen, Zhang Zhihao, Jin Jing, Song Ningfang
Opt Express. 2014 Nov 3;22(22):27228-35. doi: 10.1364/OE.22.027228.
Air-core photonic bandgap fiber (PBF) is an excellent choice for fiber optic gyroscope owing to its incomparable adaptability of environment. Strong and continuous polarization mode coupling is found in PBFs with an average intensity of ~-30 dB, but the coupling arrives at the limit when the maximum optical path difference between the primary waves and the polarization-mode-coupling-induced secondary waves reaches ~10mm, which is corresponding to the PBF length of ~110 m according to the birefringence in the PBF. Incident light with the low extinction ratio (ER) can suppress the birth of the polarization-mode-coupling-induced secondary waves, but the low-ER light obtained by the conventional Lyot depolarizers does not work here. Consequently, a large nonreciprocity and a bias error of ~13°/h are caused in the air-core photonic bandgap fiber optical gyroscope (PBFOG) with a PBF coil of ~268 m.
空心光子带隙光纤（PBF）因其无与伦比的环境适应性，是光纤陀螺仪的理想选择。在平均强度约为 -30 dB的PBF中发现了强烈且持续的偏振模式耦合，但当主波与偏振模式耦合引起的二次波之间的最大光程差达到约10mm时，耦合达到极限，根据PBF中的双折射，这对应于约110 m的PBF长度。消光比（ER）低的入射光可以抑制偏振模式耦合引起的二次波的产生，但传统Lyot消偏器获得的低ER光在此处不起作用。因此，在具有约268 m PBF线圈的空心光子带隙光纤光学陀螺仪（PBFOG）中会产生较大的非互易性和约13°/h的偏置误差。
