高信噪比随机光电振荡器  

Random Optoelectronic Oscillator with High Signal-to-Noise Ratio

作　　者：李阳[1] 余游 徐恩明[1] 张祖兴[1] Li Yang;Yu You;Xu Enming;Zhang Zuxing(Advanced Photonic Technology Lab,Nanjing University of Posts and Telecommunications,Nanjing 210023,Jiangsu,China)

机构地区：[1]南京邮电大学先进光子技术实验室,江苏南京210023

出　　处：《光学学报》2023年第20期208-215,共8页Acta Optica Sinica

基　　金：国家自然科学基金(62175116);江苏省研究生科研创新计划(KYCX22_0913)。

摘　　要：提出和研究了一种高信噪比(SNR)随机光电振荡器(ROEO)。该ROEO由随机光纤激光器与光电振荡器两部分组成,得益于随机光纤激光器中瑞利散射(RS)提供的随机分布反馈,实现了宽带随机微波信号的产生。通过在随机光纤激光器中加入另一个波分复用器(WDM),去除残余的拉曼泵浦光,提高了随机微波信号的信噪比。控制信号光的偏振态,抑制了随机腔中的受激布里渊散射(SBS)效应。实验中,获得了带宽为DC~30 GHz(DC代表直流0 Hz,表达的含义是从0 Hz到30 GHz)的随机微波信号。在DC~10 GHz范围内的信噪比约为40 dB,并且腔内的受激布里渊散射与随机微波信号的功率差达到约19.64 dB。高信噪比宽带随机微波信号在随机比特生成、雷达、安全通信等领域有重要的应用前景。Objective In recent years,optoelectronic oscillators(OEOs)have undergone rapid development due to their remarkable advantages such as high frequency,large bandwidth,and magnetic interference immunity.They are widely used to generate microwave photonic signals with ultralow phase noise level,which are mainly used in important fields such as communications,radar systems,and measurements.In the past decades,double-loop,coupled,injection-locked,and cosymmetric-time symmetry(parity-time symmetry)OEOs have been developed.These different structures of OEOs can be used to generate high-frequency microwave signals as well as complex microwave signals,such as chirped microwave signals via applied modulation,phase-locked microwave signals,and chaotic signals.However,the abovementioned OEOs rely on their own fiber cavity lengths to produce a single oscillation frequency with a limited frequency tuning range.In 2020,Prof.Ming Li's group at the Institute of Semiconductors,Chinese Academy of Sciences,proposed to combine backward Rayleigh scattering(RS)in an optical fiber with optoelectronic oscillation to realize a broadband random OEO(ROEO),and an ultra-broadband(DC-40 GHz)random microwave signal is obtained in an open cavity through backward RS.The generated signal possesses random characteristics,and its oscillation frequency was not limited by the fixed length of the resonant cavity.Random signals have potential in many applications such as random bit generation,radar systems,and electronic jamming and countermeasures.However,their open-loop noise results in a large substrate noise because of the active amplifier devices,and the random signal power is only 20 dB greater than the noise power.Schemes for improvement of the signal-to-noise ratio(SNR)of random microwave signals have not been reported.In this study,we propose an ROEO for the generation of high-SNR random microwave signals.The ROEO consists of a random fiber laser and an optoelectronic oscillation loop,which improves the SNR of random microwave signals by introdu

关 键 词：微波光子学 随机光电振荡器 瑞利散射 波分复用器 高信噪比 

分 类 号：O436[机械工程—光学工程]