【摘要】 针对光电振荡器(OEO)系统,设计了一种可实现滤波功能的串联耦合双循环延时线(SCDRDLs),并与放大自发辐射(ASE)宽带激光源、Mach-Zehnder调制器(MZM)、偏振分束器(PBS)相结合形成微波光子滤波器(MPF)。利用结构中ASE宽带激光源相干时间小于SC-DRDLs固有延时的特性,实现MPF的非相干性。同时SC-DRDLs的双循环延时线级联特性,决定系统具有大的自由频谱范围,再结合其双输出端口与PBS形成的双环结构,完成系统的高边摸抑制性能。理论分析和实验结果表明,本文系统能产生高频谱纯度、长期稳定性和低相位噪声的微波信号;通过改变SC-DRDLs的环长,可对MPF进行重构,进而调谐振荡频率。更多还原

【Abstract】 A series-coupled double recirculating delay line(SC-DRDL)with filter response is designed based on optoelectronic oscillator(OEO)system,which can form a microwave photonic filter(MPF)by combination of an amplified spontaneous emission(ASE)source,a Mach-Zehnder modulator(MZM)and a polarization beam splitter(PBS).In the structure,the incoherence can be performed due to the coherence time of the ASE source is much smaller than the delay of the SC-DRDLs.Meanwhile,the large free spectral range of the system can be obtained by series characteristics of the double recirculating delay lines for SC-DRDLs,along with utilization of the dual-loop system between the dual outputs of the SC-DRDLs and PBS,So the high sidemode suppression performance is achieved.A detailed theoretical analysis is provided,which is verified by experiment.A microwave signal with high spectral purity,longterm stability and low single-sideband(SSB)phase noise is generated.In addition,by changing the loop lengths of the SC-DRDLs,the MPF is reconfigured and the oscillation frequency of the OEO can be simply tuned.更多还原