榕树网在光互连网络中具有广泛的应用。讨论了榕树网的功能特点和连接关系,给出了其网络结构的拓扑示意图,并通过榕树网与逆榕树网的串联构成了全排列无阻塞的双榕树网络。利用偏振分束器(PBS)、相位型空间光调制器(PSLM)和反射镜设计了榕树网各级节点开关和各路由级的交换模块。它们均采用类似的结构和相同的偏振控制技术,具有结构简单、控制方便、易扩展与集成、与信号光偏振态无关和可双向交换等特点。对2×2节点开关单元的性能参数进行了测试,实验数据表明该节点开关具有插损小、串扰低、可靠性好等特点。由它所构成的全排列无阻塞双榕树网在光计算和光互连网络中会有一定的应用。

Banyan network shows promising characteristics in the practical application of optical information systems and optical interconnection networks. The properties and the connection relationships of banyan network are investigated in detail,and its topological schematic diagram is also proposed. By a cascade of the banyan network and the inverse banyan network,a full-permutation non-blocking double banyan network can be constructed. Based on the identical polarization controling technology and the same spatial structure,the node switch and the routing stage are discussed and designed by using phase spatial light modulator (PSLM),polarizing beam-splitter (PBS),and mirror. The module designed here has a number of advantages:less optical components,compact in structure,efficient in performance,bidirectional operation,and insensitive to the polarization of signal beam. The tested parameters for the 2×2 optical switch show that the full-permutation non-blocking double banyan network proposed here should be helpful in the design of large-scale optical interconnection network because of low insertion loss,low crosstalk,and high-performance.