类矩形芯光子晶体光纤的色散与偏振特性

Dispersion and polarization properties of near-rectangle core photonic crystal fibers

应用全矢量模型分析类矩形芯光子晶体光纤的色散和偏振特性 ,讨论了光纤结构参数对光纤特性的影响 .研究表明 :类矩形芯光子晶体光纤的模式双折射比普通椭圆保偏光纤至少高一个数量级 .增大光纤的相对孔径 ,可获得更高的双折射 .零走离点对应的波长也比普通椭圆保偏光纤长 ,随着孔距的增大 ,走离曲线将向长波长方向产生移位 ,零走离点发生红移 ,零走离点所对应的波长与孔距成正比 .零走离点的出现 ,将有效地抑制一阶偏振模色散 .通过调整光纤的结构参数 ,可以获得灵活的色散特性 ,在孔距Λ =2 μm ,相对孔径d Λ =0 3时 ,在波长 1 5 5 μm附近 ,获得近 4 0 0nm的超平坦色散区 .该光纤在偏振控制、色散控制和管理方面具有广泛的应用前景 .

Dispersion and polarization properties of near-rectangle core photoric crystal fibers (PCFs) were analyzed with a full vector model. The numerical results show that the modal birefringence of near-rectangle core PCF is at least one order of magnitude higher than the conventional elliptical polarization-maintaining fibers (PMFs) . In order to obtain higher birefringence, an efficient way is to increase the relative hole diameter. Zero walk-off point occurs at the longer wavelength than that of convention elliptical PMF. With increasing hole pitch, the walk-off curve and zero walk-off point would shift towards the longer wavelength region. The corresponding wavelength of zero walk-off point is in proportion to the size of the hole pitch. The occurrence of zero walk-off point can efficiently restrain the first-order polarization mode dispersion. Through choosing the suitable structural parameter of near-rectangle core PCF, we can get the more flexible dispersion properties. The approximate 400nm ultra-flatten dispersion was gotten near the wavelength 1.55 mu m for a near-rectangle core PCF with Lambda = 2 mu m and d/Lambda = 0.3. This fiber has a number of potential applications in polarization control, dispersion control and management.