优化的波导短程透镜研究

对光波导短程透镜进行优化。在无曲率奇点理想波导短程透镜的基础上，选取一般形式卷边函数，以无弯曲损耗为目标，讨论了透镜过渡区不同卷边函数形式的曲率分布，选取了最优卷边函数并给出透镜母线的特解。经过数值计算得到了优化的理想波导短程透镜的母线函数数值，完成了非球面面型的精细加工，研制出优化的理想波导短程透镜。实验测试结果表明，短程透镜在通光孔径8mm内消球差，对4mm宽的平面波束，焦距20mm的短程透镜，其焦点束斑宽度小于4μm。

Research on Optimal Geodesic Waveguide Lenses

The purpose is to optimize geodesic waveguide lenses. A general expression is chosen for the round edge of geodesic lens based on the design of perfect geodesic waveguide lenses free of singularity of curvature. The curvature in the round area is discussed for different round area functions to depress loss due to bend. An optimal round area function and a particular solution for the lens are given. Through numerical computation, the generating curve is achived. The machining of the aspheric surface is finished, and an optimized perfect geodesic waveguide lens is developed. Measurements show that the lens has no spherical aberration across the total effective aperture of 8 mm, and for a 4 mm-width beam and a lens with 20 mm focal length, the width of the focus is about 4 μm.