光谱宽度对偏振度与差分群延时关系影响的研究

Theoretical and Experimental Analysis of the Effect of Optical Spectrum Width on Degree of Polarization

理论推导出准单色光波情况下、输入信号为高斯脉冲时偏振度(DOP)与差分群延时(DGD)关系的简明解析表达式。通过对偏振度公式的理论分析,得出了DOP随DGD变化的关系由分光比以及光源的光谱宽度决定的结论。用不同光谱宽度的10Gbit/s归零(RZ)伪随机码光源实验研究了DOP与DGD的关系,实验结果表明了理论推导和分析的正确性。理论分析表明,除了分光比参数外,只有能够影响光谱宽度的参数才会对DOP-DGD关系式产生影响,如调制码型、调制啁啾和脉冲变换极限宽度等,而其它因素则与DOP-DGD关系式无关,如色散、线路啁啾以及脉冲实际宽度等。

The mathematical expression of the rdationship between degree of polarization（DOP） and differential group delay （DGD） for Gauss pulse is derived. Based on the expression,we get the conclusions that the relationship between EOP and DGD is decided by the width of optical spectrum and the splitting ratio. The theoretical analyses show that besides the splitting ratio,only the parameters which are related with the width of optical spectrum can affect the relationship of DOP-DGD, such as modulation formats, modulation chirp,and the tmasform-limit pulse width; and the other parameters can not affect the relationshi of DOP-DGD, such as fiber dispersion,line chirp,and the actual pulse width. We gave the exepriments with 10 Gbit/s RZ, pseudo random sequence to demonstrate the validity of theoretical analyses.