The structure optimization for a binary reconfigurable true time delay lines (RTTDL) based on the Mach–Zehnder interferometer (MZI) switches is proposed. Firstly, the number of the variable optical attenuator (VOA), which is generally used to make up for the imperfectness of the MZI switch and improves the RTTDL ’s flatness of broadband amplitude response and the delay accuracy, is minimized. Meanwhile, by adopting a pair of photoelectric detectors (PD) between every two MZI switches for power monitoring, the initialization time can be greatly reduced owing to the realization of the parallel initialization. On the other hand, with the help of the PDs, a continuously adjustable delay scheme is put forward by adjusting the allocation ratio of the last MZI switch. The proof-of-principle calculations are carried out to verify the optimization. The results show that the proposed optimization not only reduces the power consumption, the optical link loss and the integration volume caused by the VOAs, but also solves the problem that the binary RTTDL has only discrete delay states.

提出了基于马赫-曾德干涉仪 (MZI) 开关的二进制可重构真时延线 (RTTDL) 的结构优化。首先，尽量减少一般用来弥补MZI开关的不完善，提高RTTDL宽带幅度响应平坦度和延迟精度的可变光衰减器(VOA)的数量。同时，通过在每两个MZI开关之间采用一对光电检测器（PD）进行功率监控，由于实现了并行初始化，可以大大减少初始化时间。另一方面，在PD的帮助下，通过调整最后一个MZI开关的分配比例，提出了一种连续可调的延迟方案。进行原理验证计算以验证优化。