LAMOST传光光纤的焦比退化特性分析

为了对LAMOST传光光纤的焦比退化特性进行几何光学分析,采用光线追迹法计算了不同宏弯曲曲率半径下半圆形弯曲光纤和S形弯曲光纤的出射光斑的能量分布,并分析了由光纤宏弯曲引起的焦比退化特性.给出了不同的弯曲形式及弯曲半径影响光纤的输出光斑能量分布的定量和定性分析.结果表明,随着弯曲曲率半径的减小,输出光能量分布更加发散,焦比退化更为严重.

Analysis of focal ratio degradation of light-transmitting optical fiber in LAMOST

The focal ratio degradation(FRD) properties of optical light-transmitting fibers in LAMOST were investigated by employing the geometrical optics theory.The energy distribution and FRD characteristics of output beam spots from semi-circle bending optical fiber and S-shape bending optical fiber with different bending radii were analyzed by the ray tracing method.At last,qualitative and quantitative analyses on the intensity distribution of output light from optical fiber with different bending radii and bending patterns were conducted.The results show that as bending radius decreases,the intensity of output light is more dispersed and thus FRD increases.