基于高非线性光纤中四波混频效应的全光取样系统

All-optical sampling system using four-wave mixing in highly nonlinear fiber

为了克服高比特率光信号实时取样时所面临的高速模数转换(ADC)限制,构建了一套基于高非线性光纤(HNLF)中四波混频效应的全光等效取样系统。全光取样系统主要包括取样脉冲信号产生、全光取样门和信号处理3部分,其中全光取样门为本系统的核心部分。取样脉冲和信号共同注入到HNLF中,基于四波混频效应实现全光取样。实验中,分别以10Gb/s、40Gb/s非归零OOK信号进行了取样实验验证。实验结果表明该取样系统可以实现高速光信号的取样过程。本文取样系统结构简单,且不受光信号速率的限制,可应用于更高速率的信号测量。

To overcome the limit with high-speed analog to digital convertion （AIX2） required for real time sampling of the high-hit-rate optical signal, in this paper, an all-optical equivalent-time sampling system based on four-wave mixing （FWM） in highly nonlinear fiber （HNLF） is set up. The all-optical sampling system mainly consists of the sampling optical pulse signal unit, all-optical sampling gate unit and signal processing unit, where the all-optical sampling gate is the core of the sampling system which can complete the all-optical sampling of high-speed optical signal. The all-optical sampling is implemen- ted based on four-wave mixing effect when the sampling pulse and the signal are injected into the highly nonlinear optical fiber. In order to verify the feasibility of the sampling system, 10 Gbit/s and 40 Gbit/s not-return to-zero （NRZ） on-off keying （OOK） signals are used for the sampling experiments. Experi- mental results show that the sampling system ean achieve high-speed optical signal sampling procedure. At the same rime,the sampling system is simple,not subjeet to the limitations of the optical signal rate, and can be applied to higher-rate signal measurement.