C lens光纤准直器点精度优化分析

利用矩阵光学理论中的传输矩阵法，给出了C lens结构参数与点精度之间的函数关系式.基于该公式，论文讨论了C lens透镜的光纤出射点到倾斜面的距离d、C lens透镜折射率nl、光端面和C lens端面倾角θ、球面曲率半径R以及长度L等结构参数变化时对点精度的影响，计算结果表明：在d固定的情况下，R和L的调整范围都较小，当d=0.2 mm时，R、L改变引起点精度的改变量分别为0.019°、0.03°，造成的原因是焦距f与nl、R、L有关，且互相制约，限定了R和L的调整范围，使得点精度改变也较小；当f分别取0 mm、0.1 mm和0.2 mm时，点精度分别为-0.493°、-0.257°、-0.03°，其原因是要有效地降低点精度，需要R、L、d中的任意两个参数改变；利用论文得到的计算公式可以分析不同类型的光纤准直器的点精度，并得出其点精度合适的优化途径.

Analysis of Point Accuracy for C Lens Fiber Collimator

The functional relationship between C lens structure parameters and point accuracy is given using the transfer matrix method. Based on this formula, the influence of structural parameters, including the distance d between the point of the incident fiber and the inclined surface, the refractive index of the C lens lens nl, the inclination angle θ between the optical end surface and the C lens end surface, the spherical curvature radius R and the length L, on the point accuracy are discussed. The calculation results show that when d is fixed, the adjustment ranges of R and L are both small. For example, when d is 0.2 mm, the changes of point accuracy caused by R and L are 0.019° and 0.03° respectively. This is because the focal length f is related to nl, R, and L and restricts each other, so that the point accuracy changes less. It is calculated that when the f is 0mm, 0.1mm, and 0.2mm respectively, the point accuracy corresponding to the maximum working distance is -0.493°, -0.257°, -0.03°.The reason is that among the parameters of R, L, and d, point accuracy can be changed effectively when at least any two of the parameters be changed at the same time. According to the point accuracy formula, the point accuracy of different types of C lens can be analyzed and a suitable optimization method can be obtained.