Opt Lett. 2018 Nov 15;43(22):5563-5566. doi: 10.1364/OL.43.005563.
We experimentally demonstrate a scalable and reconfigurable optical tapped-delay-line (TDL) for multichannel equalization and correlation of 20-Gbaud quadrature-phase-shift-keyed (QPSK) signals using nonlinear wave mixing and a microresonator Kerr frequency comb. The optical TDL mainly consists of two stages: one being a multicasting of the original signals in a periodically poled lithium niobate (PPLN) waveguide with Kerr comb lines functioning as mutually coherent pumps, while the other is a coherent multiplexing of the delayed and weighted signal replicas in a second PPLN. A two- or three-tap optical TDL is demonstrated to simultaneously equalize a distorted QPSK data signal, reducing the error vector magnitude (EVM) from 22.5% to either 19.9% or 18.2%, and search two- or three-symbol patterns on another QPSK signal.
我们通过非线性波混频和微谐振器克尔频梳实验演示了一种可扩展且可重构的光抽头延迟线（TDL），用于 20-Gbaud 正交相移键控（QPSK）信号的多通道均衡和相关。光 TDL 主要由两个阶段组成：一个阶段是在周期性极化铌酸锂（PPLN）波导中对原始信号进行多路复用，克尔梳线作为相互相干的泵浦，而另一个阶段是在第二个 PPLN 中对延迟和加权信号副本进行相干复用。演示了一个两抽头或三抽头光 TDL，可同时均衡失真的 QPSK 数据信号，将误差向量幅度（EVM）从 22.5%降低到 19.9%或 18.2%，并搜索另一个 QPSK 信号的两个或三个符号模式。
