五角芯型保偏光子晶体光纤(Q-PM-PCF)的双折射

Birefringence of quinquangular-core polarization-maintaining photonic crystal fiber

提出了一种内层空气孔环含有五个空气孔的新型高双折射光子晶体光纤结构;采用全矢量有限元法进行分析,研究了该光子晶体光纤两正交偏振模的有效折射率和双折射,分别给出了该五角芯型保偏光子晶体光纤双折射随输入光波长和大空气孔半径的变化曲线。分析结果表明:该五角芯型保偏光子晶体光纤的双折射很易达到10-3量级甚至更高,比传统保偏光纤的双折射至少高出一个数量级,合理设计光纤结构参数,该保偏光纤的双折射在1550 nm处可以达到6.5×10-3以上,甚至更高,适合应用于偏振特性及稳定性要求都较高的实际光纤传感系统,例如光纤陀螺。

A novel highly birefringent photonic crystal fiber structure with five air-holes in the internal layer was proposed and analyzed by using a full-vector finite method（FEM）.The effective indices of two orthogonal polarization modes and the birefringence of the new PCF were investigated.The curves showing the relation between the birefringence of this PCF and the wavelength of the input light as well as the radius of larger air holes were given.From the numerical results it is found that,the birefringence of the new polarization maintaining photonic crystal fiber can easily achieve the order of 10-3,which is at least one order of magnitude higher than that of standard birefringent ones.It is shown that it may exhibit birefringence as high as 6.5×10-3 at wavelength of 1550 nm,or even higher.It can well satisfy the application of real optical sensing systems which need high polarization and reliability,e.g.fiber optic gyroscope.