Graded Index (GRIN) Lenses,What is GRIN lenses,GRIN lenses are short cylindrical lengths of glass with a graded refractive index: the index decreases with the square of the distance from the axis of the lens. GRIN lenses are very similar to graded index fibre and are sometimes called SELFOC lenses.,Spherical lens (3)角度:以光轴或端面法线为基轴,从基轴向光线转动, 顺时针为负,逆时针为正; (4)标记:在成象图中出现的几何量(长度和角度)均取绝 对值,正量直接标注,负量冠以“-号之后标注。,透镜成像矩阵,总成像矩阵,利用透镜传输矩阵S进行简化:,GRIN透镜的成像（I）,GRIN透镜的成像（II）,GRIN透镜的成像（III）,GRIN透镜的成像（IV）,GRIN透镜的成像（V）,GRIN透镜的成像（VI）,透镜成像性质,表,GRIN透镜的应用：准直-聚焦,0.25P lens:on axis,0.25P lens：off axis,GRIN透镜的应用：光源耦合,0.23P lens：angle compress,0.29P lens：facula compress,自聚焦透镜的重要特性,重要性能参数： 焦距：f = -1/n0A1/2sin(A1/2L) 聚焦参数：A = 2D/a2 数值孔径：NA = n0(2D)1/2 节距：P = 2p/A1/2 成像特性：与透镜长度有关： 1/4 节距透镜 1/2 节距透镜 0.23节距透镜 0.29 节距透镜,