基于双波长双并联调制的大动态范围微波光子链路

High Dynamic Range Microwave Photonic Link Based on Dual-Wavelength Dual-Parallel Modulation

为改善微波光子链路的动态范围,提出了一种基于双波长双并联调制的线性化方法。仿真分析了激光器输出光功率漂移对该线性化链路无杂散动态范围的影响,结果显示基于现有的商用器件即可实现该线性化方法。此外,实验对比了单调制器基本链路和双波长双并联调制线性化链路的性能。实验结果显示,线性化后,链路的压缩动态范围提高了1.5 d B,无杂散动态范围提高了15.6 d B,其中无杂散动态范围可达到122.5 d B·Hz4/5。该线性化方法简单、易实现,为光链路动态范围要求较高的应用领域提供了一种很好的解决方案。

A linearization method based on dual-wavelength dual-parallel modulation is proposed to enhance the dynamic range of microwave photonic link. The exacerbation of spurious-free dynamic range of linearized link due to the drift of the optical power of lasers is simulated. The simulation results show that this linearization method can be performed by using commercially available devices. Furthermore, the performances of a single-Mach-Zehnder modulator （MZM） intrinsic link and a dual-wavelength dual parallel modulation linearized link are compared in the experiment. The measurement results show that 1.5 dB enhancement of compression dynamic range and 15.6 dB of improvement spurious-free dynamic range are achieved after linearization. The spurious-free dynamic range of linearized link is up to 122.5 dB · Hz4/5. In a word, this linearization method is a good alternative for improving the dynamic range of optical links.