庞加莱球方法对非线性相干耦合模在低双折射光纤中的偏振态稳定性分析(英文)

Polarization stability analysis of nonlinear coherent coupling by using Poincaré sphere in a weakly birefringent fiber

通过对低双折射非线性相干耦合模传输方程引入斯托克斯参量表达式,利用庞加莱球图示法,分析了非线性相干耦合波在低双折射光纤中偏振态的衍化规律,并运用相图法数学几何法给出了双折射差与偏振不稳定性的关系,临街功率表达式。当两个运动常量满足关系时,偏振态围绕庞加莱球上的P1,P2稳定点旋转的闭合曲线衍化,并呈现椭圆偏振态;当两个运动常量满足关系时,出现保偏现象;当两个运动常量满足关系时,偏振态围绕P1,P3稳定点旋转的闭合曲线衍化。

Nonlinear polarization evolution for different birefringence regions in a weakly birefringent fiber was analysed by using Poincare sphere. It was derived by quoting the Stoke＇s parameters formalism in the nonlinear coupled differential equations for the nonlinear coupled-mode. The phase plane method shows how the evolution of polarization was governed by refringence. Three conditions was derived for different initial values. While the two constants of motion allow for the inequality -R〉Г, the polarization state would either be elliptical or spin around the stable singular points P1 and P2 on the Poincare sphere. For the inequality -R=Г, the linear polarization maintaing phenomenon would occur, the critical power for polarization instability was obtained by using geometrical methods. For the inequality -R〈Г〈R, the evolution of polarization state would spin around the two points fixed point P and P3 on the Poincare sphere.