鉴于榕树网在自由空间光子交换网络中具有重要的应用价值,分析了榕树网的特点和4×4二维榕树网的空间拓扑结构,通过偏振光分光棱镜、微闪耀光栅阵列、平面反射镜、半反半透镜和液晶空间光调制器的集成,构建二维的榕树交换网实验模块,利用微闪耀光栅的衍射特性,控制每块微闪耀光栅的周期,以实现入射光信号不同方向的闪耀输出,最终完成二维榕树网自由空间水平和竖直方向上的交叉互连,直通则由平面镜反射实现。对二维榕树网实验模块的功能分析表明,该实验模块理论上可以完成4×4二维面阵内光信号(或数据)的排序、交换、组播、广播、矩阵变换等操作,具有交换透明、速度快、空间带宽高等特点,在全光交换和光通信中具有一定的应用。

Banyan optical networks play an important role in free-spatial photonic networks. The characteristics and structures of two-dimensional (2D) banyan network are analyzed. A new 2D banyan network architecture, which consists of polarizing beam-splitters, 4×4 micro blazed-grating arrays, half silvered mirrors, 4×4 spatial light modulators and mirrors, is proposed to accomplish optical signal switching, multicasting, broadcasting and matrix conversion through the 4×4 2D planes. The 4×4 micro blazed-grating arrays fulfill vertical connection and horizontal connection switching in 2D banyan networks, while the mirrors perform straight connections. The theoretical analysis shows that the architecture has the advantages of transparent switching, high speed, and high space-bandwidth product, therefore it can be implemented in free spatial optical interconnection widely.