异形截面单纤维光学特性的数值模拟

Numerical Simulation of Optical Properties on Single Non-Circular Cross-Section Fiber

建立异形纤维的横截面模型,并提取截面特征参数进行光学特性的模拟计算.理论上分析了圆形、四叶形和三叶形截面之间的一次折射光强比和折射光方向的差异性,总体上一次相对折射光强比Irz大致在0.95～0.96范围内变化,三叶形截面和四叶形截面的折射光与y轴正向夹角βt变化较圆形截面的单调变化更为复杂,呈非单调变化.从几何光学角度分析了三叶形和四叶形对纤维内部折射光和透射光变化的影响,表明四叶形对光路变化的影响更明显.

The models of non-circular cross-section fibers were established,and the characteristic parameters of non-circular cross-section fibers using in this numerical simulation were extracted.Furthermore,the differences of refracted light intensity ratio and direction of refracted light among circular,quadri-lobal and trilobal cross-section fibers were analysed theoretically.The results showed that the refracted light intensity ratios（Irz） of these fibers were in the range of 0.950.96,both the quadri-lobal and trilobal cross-section fibers＇ βt which was the angle of refracted light to y axis changed non-monotonically and much more intricately than that of circular cross-section fibers.Moreover,according to the theory of geometrical optics,the effect of trilobal and quadri-lobal shapes on the changes of internal refracted light and transmitted light in fibers were also conducted,and the result suggested that the refracted and transmitted light was changed more effectively by quadri-lobal cross-section fiber.