摘要
针对正方形自聚焦透镜折射率分布特点,引入方向角概念,以平方律表征其折射率分布.从理论上研究了平方律折射率分布下正方形自聚焦透镜的光线轨迹方程,得到了子午光线表达式.结果表明,与传统径向自聚焦透镜相比,正方形自聚焦透镜的光线轨迹受光线入射方向角影响,会产生较大像差.得到了正方形自聚焦透镜数值孔径表达式,表明数值孔径并非常量,且与方向角密切相关.计算了中心轴上的最大数值孔径,方向角为0°时最小为0.405,方向角为45°时最大值0.5以上.
The refractive-index distribution of square seifoc lens （GRIN） was analyzed by Matlab software. Based on the characteristic, square law function was brought forward to figure the refractive-index distribution. The computation results are well agreement with the exqerimental results. The ray tracing in the square GRIN lens was studied, the meridian ray tracing equation and numerical aperture equation were got. The mumerical aperture relates to the directions amgle as well, when the directions angle is 0, the largest numerical aperture is 0. 405 and it can be up to around 0.5 when the directions angle is π/4.
出处
《光子学报》
EI
CAS
CSCD
北大核心
2008年第9期1739-1742,共4页
Acta Photonica Sinica
基金
西南科技大学引进人才基金(053102)资助
关键词
正方形自聚焦透镜
折射率分布
子午光线轨迹
数值孔径
Square GRIN lenses
Refractive index distributing
Meridian ray tracing
Numerical aperture
