保偏空芯带隙光子晶体光纤温度特性研究

Analysis of Thermal Properties in a Polarization-Maintaining Air-Core Photonic Bandgap Fiber

提出了一种具有良好保偏(PM)特性的空芯带隙光子晶体光纤(PBF)结构,利用全矢量有限元方法(FEM)对光纤有效折射率、拍长及限制损耗特性受温度波动的影响进行了研究。研究结果表明,在1.55μm波长处,该PBF的双折射高达6.19×10-3,拍长不超过0.25 mm;PBF拍长对温度波动不敏感,拍长温度敏感系数低于2.86×10-8m/℃,比常规的熊猫保偏光纤低两个数量级;光纤损耗对温度波动较为敏感,两正交偏振态限制损耗会随温度提高而增大。这种具有极低拍长温度敏感系数的PM-PBF可以有效降低谐振式光纤陀螺(RFOG)中热致偏振不稳定带来的误差,在RFOG、光纤通讯、光纤传感等领域具有重要的应用价值。

A kind of air-core photonic band gap fiber（PBF） with outstanding polarization-maintaining（PM）property is proposed. The effects of temperature variation on the effective index, beat-length and confinement loss are studied numerically based on full vector finite element method（FEM）. It is found that the birefringence of the PBF is as high as 6.19×10-3, and beat-length is as short as 0.25 mm at the wavelength of 1.55 μm. The beat-length of this PBF is insensitive to the temperature, and the temperature-dependent beat-length coefficient is as low as2.86×10-8m/℃, which is typically two orders of magnitude lower than those of conventional panda fibers. The loss of the PBF is sensitive to temperature, and the confinement loss of the two orthogonal polarized modes increases with the increasing temperature. The PM-PBF with ultra-low temperature-dependent beat-length coefficient can reduce errors induced by the thermall polarization crosstalk apparently in interferometric applications such as resonant fiber optic gyroscope（RFOG）, which plays an important role in RFOG, optical communications, optical fiber sensors and so on.