设计了一个无顶六角棱镜,该棱镜的六个侧面分为3+3两组,每组与棱镜底面夹角不同。扩束后的平面波经棱镜六个侧面折射后产生干涉光场图案,干涉图案对应双周期渐变光子晶体超晶格结构,利用光敏介质记录该结构即可得到渐变光子晶体透镜阵列。通过调整棱镜两组侧面与底面夹角、两组光束的振幅对比度等参量,可以设计阵列周期、渐变梯度、中心与边缘折射率差不同的透镜及阵列结构。本研究可为渐变透镜在光互联、光集成、光耦合、显示及成像方面的应用提供新思路。

In this work, a top-cut hexagonal prism is designed. The six sides of the prism are divided into two equal groups, in which the angles between the side and the bottom of the prism are different. When an expanded plane wave is refracted by the six sides of the prism, the interference pattern can be formed, which is corresponding to a two-period superlattice structure of gradient photonic crystal (GPC). If the interfered pattern is recorded by a photosensitive medium, a GPC lens array is obtained. By adjusting the angle between the side and bottom of the prism and the amplitude contrast of both groups of beams, we can design lenses and arrays with different array periods, gradients, and refractive index differences between the center and edge of each lens. This work provides new applications for gradient lenses in optical interconnection, optical integration, optical coupling, display, and imaging.