基于双平行马赫-曾德尔调制器和平衡光电探测器的四倍频可调对称三角形函数波形信号发生器  

Generator of Signals with Quadruple Frequency and Triangular Waveform Tunable in Symmetry Based on Dual-Parallel Mach-Zehnder Modulator and Balanced Photodetector

作　　者：刘元 李晶[1] 贺永娇 朱伟 宁提纲[1] 裴丽[1] Liu Yuan;Li Jing;He Yongjiao;Zhu Wei;Ning Tigang;Pei Li(Institute of Lightwave Technology,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学光波技术研究所,北京100044

出　　处：《光学学报》2021年第19期98-104,共7页Acta Optica Sinica

基　　金：国家重点研发计划(2019YFB2204003)。

摘　　要：提出并研究了一种基于双平行马赫-曾德尔调制和平衡光探测的四倍频可调对称三角形函数波形信号发生器。将调制非线性和多参量调控应用到可调对称三角形波形信号的产生中,可实现四倍频信号输出。通过调整调制系数β和时延量τ,可实现光电流表达式向目标函数波形微波信号傅里叶展开式前三项的近似表征,最后得到四倍于射频调制频率的周期性三角形波形信号。结合仿真研究,实现了5 GHz射频调制频率下,20 GHz三角形波形信号的输出,通过引入拟合误差对所获得的时域波形进行误差估计,所提出的发生器可实现对称系数20%到80%之间的波形输出,且可保证拟合误差小于8%。This paper proposed a generator of signals with a quadruple frequency and a triangular waveform tunable in symmetry based on the dual-parallel Mach-Zehnder modulator and balanced photodetector. In the scheme, modulation nonlinearity and multiparameter manipulation are used to generate the target signals. An approximate characterization of the photocurrent expression using the first three terms of the Fourier expansion of microwave signals following the objective function can be achieved via the adjustments of the modulation index β and time delay τ. As a result, signals with a periodic triangular waveform and a frequency four times the RF modulation frequency are obtained. In the simulation verification, 20 GHz signals with a triangular waveform are output at an RF modulation frequency of 5 GHz. Based on the fitting error, the error of the obtained time-domain waveform can be evaluated. The designed generator is capable of outputting signals with a symmetry factor between 20% and 80% while ensuring the fitting error within 8%.

关 键 词：光纤光学 光纤通信 微波光子 对称性可调 四倍频 马赫-曾德尔调制器 

分 类 号：TN929.1[电子电信—通信与信息系统]