偏振模色散和时延抖动对啁啾光纤光栅色散补偿特性的影响

对存在偏振模色散(PMD)和群时延(GD)抖动的非理想线性啁啾光纤光栅的色散补偿特性进行了研究。实验测量了啁啾光纤光栅的群时延谱和偏振模色散光谱，理论分析和实验测量表明，啁啾光纤光栅差分群时延(DGD)抖动与其时延抖动密切相关。通过数值模拟方法，计算了线性啁啾光纤光栅偏振模色散眼图代价与入射到啁啾光纤光栅色散补偿器的光信号的偏振方向的关系，计算结果表明在使用啁啾光纤光栅色散补偿器时应对光信号的偏振方向进行调整，以获得最佳补偿效果。另外结合实验数据，模拟计算并讨论了非理想线性啁啾光纤光栅群时延抖动和偏振模色散引起的信号的展宽和脉冲形状的劣化。

Influence of Polarization Mode Dispersion and Group Time Delay Ripple on Dispersion Compensation by Chirped Fiber Grating

Influence of polarization mode dispersion (PMD) and group time delay ripple of the chirped fiber grating on dispersion compensation were investigated in this paper. It is shown experimentally that ripple of polarization-dependent differential group delay (DGD) has very similar variation behavior with the ripple of group delay (GD) in their spectra, though the former amplitude is about 40 times higher than the later. The minimum period of the ripples was measured to be 0.024 nm. A simplified theory is proposed to explain the similarity qualitatively. Simulations show that PMD and DGD ripples bring harmful influence to the dispersion compensation using the chirped fiber grating in high-speed optical transmission system. The relation between the incident polarization direction to the principal states of polarization (PSP) and the power penalty was calculated both by an approximate formula and numerical simulation. Simulations on eye patterns show that PMD of the linear chirped fiber Bragg grating (FBG) lowers the effectiveness of its dispersion compensation and worsens the performances of the communication in longer transmission length.