基于光子晶体光纤的光时域展宽预处理器

Time Stretch Preprocessor Based on The Photonic Crystal Fiber

模数转换器的采样速率和模拟带宽能通过预处理器得到提高。时域展宽就是一个可以提高电子数字转换器性能的技术,它是将模拟信号在数字化前减缓其速度,以实现实时采样。我们证明了1.56TSa/s超高采样率的实时模数转换器,它是通过基于大色散光子晶体光纤的时域展宽预处理完成的。该预处理器利用了大色散光子晶体光纤,将高速的光载波在时域进行大比例展宽,在数字化时处理的是被展宽的信号,因此可以得到超高的采样率。基于大色散光子晶体光纤的时域展宽预处理器不仅能大大缩短所用光纤长度,减小光纤传输损耗,而且还能减少多个掺铒光纤放大器对载波信号带来的畸变。

The performance of analog-to-digital converter （ADC） can be greatly enhanced by preprocessing the ultrafast analog signal. The time stretch technique is such a technique that boosts the performance of an electronic digitizer by slowing down the electrical signal. Demonstrated here is a real time ADC based on preprocessor of large dispersion photonic crystal fiber （PCF） that has 1.56TSa/s ultra-high sampling rate. The preprocessor based on large dispersion PCF stretches high-speed optical carrier wave with large rate. Therefor the digitizer deals with the stretched signal, and ultra-high sampling rate can be reached to realize real-time sampling. The preprocessor can not only significantly reduce the used fibers and transmission attenuation, but also reduce influence from several erbium-doped fiber amplifiers （EDFAs）.