高双折射光子晶体光纤的偏振特性研究

Polarization Properties of High Birefringence Photonic Crystal Fiber

基于超格子构造法,采用全矢量模型研究具有中心缺陷孔的椭圆孔光子晶体光纤(EHPCF)的偏振特性。研究表明,与相同结构参量的椭圆孔光子晶体光纤相比,具有中心缺陷孔的椭圆孔光子晶体光纤具有更大的模式双折射和走离参数。双折射、走离参数与频率的依赖关系与普通保偏光纤存在很大差别。走离参数在低频区出现零走离点,这为在该光纤中既保持高双折射又实现零走离单模运转提供了可能。适量增加中心缺陷孔,包层椭圆孔的椭圆率及面积可以获得高的双折射和大的走离参数。

Based on the supercell overlapping method the full vector model was adopted to model polarization properties of elliptical-hole photonic crystal fiber (EHPCF) with central defect hole. It was found that this EHPCF with central defect hole has a larger birefringence and walkoff parameter than the solid core EHPCF does. The dependence of birefringence and walkoff parameter on frequency is different from that of the conventional polarization maintaining fiber. A zero walkoff point occurs at the low frequency region in this photonics crystal fiber (PCF). This offers the possibility that the single mode operates at high birefringence and zero-walkoff at a given wavelength. High birefringence and large walkoff parameter can be obtained by a moderate increase in the central defect hole in the core region and the cladding elliptical hole area and ellipticity.