应用耦合模理论研究光在圆对称双包层光纤中的传输(英文)

为了深入理解双包层光纤的光场传输特性,应用耦合模理论将双包层光纤等效为相互耦合的单模光纤和环形芯光纤,研究了圆对称的双包层光纤的光场传输.通过计算单模光纤LP01模和环形芯光纤导模的耦合系数发现了环形芯光纤LP0n模的耦合系数远大于其它导模的耦合系数,且LP0n模中的高阶模比低阶模的耦合系数大.据此,应用耦合模理论计算得到了该双包层光纤的光传输特性,计算结果发现光场沿光纤轴向呈近似周期分布,且纤芯中光功率变化的平均周期随波长递增,但平均归一化功率与光纤参数紧的选择有关.

Light Propagation in a Circular Double Clad Fiber Using Coupled Mode Method

For better understanding the light propagation in a double clad fiber (DCF), the perfect circular double clad fiber is numerically investigated by using the coupled mode method with translating the DCF into a single mode fiber (SMF) and an annular core fiber (ACF).The coupling coefficients between the LP01 mode of the SMF and the guided modes of the ACF are calculated. The results show that the LP0n modes of the ACF have greater coupling coefficients than the other guided modes, and for the LP0n modes the coupling coefficient of the high-order mode is larger than that of the low-order mode. The field distribution in the DCF core calculated by the coupled mode equations shows a quasi-periodic distribution along the DCF. The average period of the field distribution increases with the increasing of wavelength for different DCF parameters and the average normalized power of the field distribution is closely related to the chosen parameters of the DCF.