基于Zemax分析双包层光纤吸收效率的新方法

Absorption efficiency of double-clad fiber based on Zemax

计算双包层形状对光纤吸收效率的影响,常用的方法有二维射线法、三维射线法、光纤光学波动耦合理论等。介绍了一种基于Zemax软件计算其吸收效率的三维方法,通过编写ZPL宏计算了圆形、偏心形、矩形、D形、八角形等常规内包层形状对光纤吸收效率的影响,并将分析结果与二维射线法所得结果进行比较,数据表明:本文的计算结果和二维射线法的计算结果类似,各种内包层形状光纤的吸收效率趋势是一样的。它的优点在于本文给出的是吸收效率和光纤长度的关系,更形象直观,而二维射线法给出的是吸收效率和反射次数的关系;在Zemax中可以设置光线的临界角,而二维射线法是假设光线从内包层里任意一点随机发射的,它没有考虑到光线在内包层中发生全反射的条件,本文的计算结果更准确一些;在Zemax里可以构建各种内包层形状,它的非序列光线追迹速度很快,以矩形内包层光纤为例,在同样的条件下利用Ze-max用时373s,利用二维射线法用时1 732s,所以基于Zemax分析双包层光纤吸收效率的方法计算速度更快。最后用这种方法研究了上海光机所楼祺洪研究员提出的一种新型双包层光纤的吸收效率。

In order to calculate the absorption efficiency of different double-clad optical fibers, two-dimensional analysis, three-dimensional analysis and fiber optics wave coupling theory were adopted in the past. A 3-D method based on Zemax software was introduced in this paper, the absorption efficiency of circular, offset, rectangular, D-shape, octagonal double-clad fibers were investigated by writing ZPL macros, and the results were compared with the data obtained from the 2-D analysis. Data showed that two results were similar and the absorption efficiency trends of different inner-clad fibers were same. The solution based on Zemax had many advantages in comparison with the 2-D analysis. The simulation based on Zemax was more vivid because the relationship between the absorption efficiency and fiber length could be achieved, however, the relationship between the absorption efficiency and reflection times was obtained based on the 2-D analysis. The critical angle could be set in Zemax, rays with arbitrary angle were emitted from the arbitrary point in the inner-clad section in the 2-D analysis ignoring ray total reflection condition in the inner-clad, so the result based on Zemax was more accurate. It was easy to simulate the different inner-clad shapes and the non-sequential ray tracing velocity was very fast, the operation time based on Zemax was 373 seconds, and was 1 732 seconds based on 2-D analysis under the same condition for the same rectangular innerclad fiber,so the calculate speed based on Zemax was more rapid. The absorption efficiency of a new structure double-clad fiber put forward by professor LOU Qi-hong was calculated finally.