Study and Design of Hybrid Triplet Lens

This study presents a new method for designing algorithm for a triplet lens with one or two elements that are made of a gradient index medium (GRIN). This method is based upon considering a well-known designed triplet lens (Cooke triplet lens) as a target lens for designing of the Hybrid Triplet Lens (HTL). Our design was based upon keeping the total optical path length for the axial ray fixed for each case of design. The results showed that several designs for the HTL have the same total powers of the target lens. These designs depend on the variation of the GRIN element parameter values and the order of the GRIN element position in the system. These HTL designs have been evaluated by considering several optical merit functions, i.e., the root mean square (RMS) spot radius, wave front error and the spherical aberration. To achieve the optimal design, these functions are compared for the target lens and the HTL designs through a wide range of field angles.

用焦散面趋于最小的方法优化三元和四元透镜系统

一般地,对于成象光学系统,最好是把点光源转换成分布在具有适当放大率焦平面上的点象。实际上,实现这一点的方法是改变透镜系统参数,使得每个物点光束在象平面上的扩展最小。本文对焦散面提出了一种评价函数,可描述理想象点焦散面的扩展。该焦散评价函数已用于优化三元和四元透镜系统。将作为视场角函数的均方根弥散圆半径与用传统方法设计的类似透镜比较,评价了优化透镜的性能。对于优化透镜系统,在于提高平均均方根值。结果表明,焦散评价函数最小时,可以缩小整个视场的均方根弥散圆半径和透镜系统的象差,对大孔径和大视场的光学系统尤其如此。