光子晶体光纤超连续谱的产生与偏振特性

通过研究飞秒脉冲在双折射光子晶体光纤反常色散区传输时的偏振特性及对超连续谱展宽的影响,发现在偏振方向与光纤快轴或慢轴重合时,其输出的超连续谱具很好的线偏振.当偏振方向与快轴夹角为45 °时,其输出基本上是圆偏振.由于高的双折射光子晶体光纤有高的非线性和三阶色散,所以可产生高偏振性的超连续谱.脉冲偏振方向与光纤快轴不同夹...

SUPERCONTINUUM GENERATION AND POLARIZATION OF PHOTONIC CRYSTAL FIBERS

We investigate the propagation of femtosecond pulses in the anomalous dispersion region of a birefregent photonic crystal fiber and the effect of its polarization on the broadening of the generated supercontinuum. It is found that the generated supercontinum exhibits a good linear polarization when the femtosecond pulse is coupled into the fiber with its polarization along the fast or slow axis of the photonic crystal fiber. When the angle between the polarization of the input femtosecond pulse and the fast axis is equal to 45 degree, the output supercontinum is circularly polarized. Since photonic crystal fibers with large birefringence usually possess high nonlinearity and third-order dispersion, they can be employed to produce supercontinuum with good polarization. The spectrum of supercontinum changes regularly when the angle between the pulse polarization and the fast aixs of the photonic crystal fiber is varied. A flat spectrum is observed when the angle is close to 45 degree. The experimental observations indicate that solid-core photonic crystal fibers with large birefregent can be used to generate supercontinuum with good linear polarization.