熔锥光纤定向耦合理论

COUPLING THEORY OF FUSED BICONICAL FIBER

提出了一种分析熔锥光纤定向耦合器及其衍生器件的新数理模型。通过把基模场的高斯理论发展到双包层光纤,并采用正态分布函数来描述耦合区的几何形态,较为完善清晰地反映了模场及边界的渐变特性。导出了本地标量场耦合系数的简洁解析式及其矢量修正式。具体器件的理论计算与实验相符较好。

A new calculating model is proposed to analyse the single mode fiber biconical couplers and the derivative devices. The gradually variations of boundary and mode field of the devices are expresed clearly and perfectly by developing the Gaussian theory of fundamental mode field of fiber for the doubly cladding-single mode fiber, and by employing a normal function to describe the tapered geometry of the devices. From these, a brief expression of scalar local coupling coefficient and its vector correction are obtained. The theoretical design and the experimental result are a good match.