基于光注入的高效率任意波形谐波下变频  

High-Efficiency Arbitrary Waveform Harmonic Down-Conversion Based on Optical Injection

作　　者：张鑫[1] 陈树文 徐向明 黎飞宇 朱华涛 Zhang Xin;Chen Shuwen;Xu Xiangming;Li Feiyu;Zhu Huatao(College of Information and Communication,National University of Defense Technology,Wuhan 430010,Hubei,China)

机构地区：[1]国防科技大学信息通信学院,湖北武汉430010

出　　处：《光学学报》2024年第22期220-228,共9页Acta Optica Sinica

基　　金：国家自然科学基金(62301569);国防科技大学自主创新科学基金(ZK24-40,23-XXXX-41)。

摘　　要：雷达的分辨率主要取决于探测信号的瞬时带宽,高精度探测和成像需要高频大带宽雷达信号,接收前端则需要对信号进行下变频处理,从而减小接收端体积、降低信号处理难度,满足小型化、低时延要求。而传统方法很难对其进行有效处理。本文基于自振光频梳及边带放大注入锁定效应,实现了对高频任意波形信号的高效率下变频。该方案基于光电振荡的增益开关自振光频梳为下变频提供了高质量、超大带宽的谐波本振信号,从而无需外部信号源。边带放大注入锁定效应为接收信号提供了高增益。40 GHz下变频为426 MHz信号的变频效率为13.034 dB。实验结果表明,周期为0.1μs以上、带宽低于2 GHz的任意波形信号均能实现高效率下变频,并且具有频谱均衡能力,在合适的输入功率下,传输带宽可达6 GHz。Objective Radar plays a crucial role in both military and civilian applications,such as weather forecasting,autonomous driving,target recognition and tracking,vital signs monitoring,military surveying,and mapping.To meet the demands for high-precision and real-time detection and imaging,radar receivers must down-convert high-frequency,largebandwidth arbitrary waveform signals to reduce the complexity of back-end processing and facilitate system miniaturization.The down-conversion system should provide high-frequency local oscillation(LO)and high gain for the modulated signal to achieve efficient down-conversion. Traditional methods of LO generation often rely on external signal sources or multiplemodulators, adding to system complexity. Furthermore, broadband arbitrary waveform signals require a flat gain spectrumto preserve their original characteristics. In this paper, we propose a scheme to achieve efficient down-conversion byproviding self-oscillation and high-frequency LO with flat and high gain.Methods This high-efficiency arbitrary waveform harmonic down-conversion is achieved through optical injection. First,a high-quality optical frequency comb (OFC) is generated by optoelectronic oscillation, leveraging the gain-switchingsemiconductor laser. The OFC’s bandwidth is enhanced through the optical injection locking of one comb line. The highfrequencyLO is then obtained. The arbitrary waveform signal is modulated onto the optical carrier. After being injectedinto the slave laser (SL), the -1st sideband is amplified and continuously locks the SL wavelength. As both the OFCcomb and the sideband are coherent with the same optical carrier, the high-frequency arbitrary waveform can be downconvertedby beating with the nearest comb line in a parallel structure. An optical delay line is used to adjust the opticalpath difference between the two branches. A wavelength selective switch filters out the unwanted comb lines of the OFC.Results and Discussions A 40 and 39 GHz microwave signal with a power level of −20 dB

关 键 词：光电子学 下变频 光频梳 光注入 雷达信号 

分 类 号：TN958.94[电子电信—信号与信息处理]