The optical rogue wave (RW), known as a short-lived extraordinarily high amplitude dynamics phenomenon with small appearing probabilities, plays an important role in revealing and understanding the fundamental physics of nonlinear wave propagations in optical systems. The random fiber laser (RFL), featured with cavity-free and “modeless” structure, has opened up new avenues for fundamental physics research and potential practical applications combining nonlinear optics and laser physics. Here, the extreme event of optical RW induced by noise-driven modulation instability that interacts with the cascaded stimulated Brillouin scattering, the quasi-phase-matched four-wave mixing as well as the random mode resonance process is observed in a Brillouin random fiber laser comb (BRFLC). Temporal and statistical characteristics of the RWs concerning their emergence and evolution are experimentally explored and analyzed. Specifically, temporally localized structures with high intensities including chair-like pulses with a sharp leading edge followed by a trailing plateau appear frequently in the BRFLC output, which can evolve to chair-like RW pulses with adjustable pulse duration and amplitude under controlled conditions. This investigation provides a deep insight into the extreme event of RWs and paves the way for RW manipulation for its generation and elimination in RFLs through adapted laser configuration.

提出了一种基于切比雪夫馈电网络的13×14开口谐振环天线阵列。该天线阵列由天线单元和切比雪夫馈电网络组成。根据八木天线原理，该天线阵列设计的辐射贴片作为天线单元的引向器，金属地面作为反射器；辐射贴片由开口谐振环结构以及I型谐振结构组成，增强天线单元的辐射能力并提高增益；天线单元的馈电端由圆弧单极子组成，提高调节天线单元阻抗匹配的灵活性；电流矩阵指导非均匀电流分布切比雪夫馈电网络的设计，减小天线阵列的旁瓣；天线单元竖直插入馈电网络的基板，减少带有馈电网络阵列的口径大小。通过实物加工后，测试结果表明，该天线阵列在工作频率点10.1 GHz处实现了22.3 dBi的增益，E面和H面旁瓣电平分别为−16 dB和−17.66 dB，具有高增益、低副瓣的特点。

单谐振腔束团长度监测器利用谐振腔内的两个本征模式测量ps量级的电子束团长度，它的关键是如何将两个不同频率的模式互不干扰地耦合提取出来。为解决这个问题，基于低通和带通滤波器的理论，提出了同轴滤波耦合结构和膜片加载波导滤波结构，借助CST微波工作室对滤波器进行建模并仿真得到其S参数。为测试耦合器的应用效果，设计了一套带有该耦合结构的单谐振腔束团长度监测器探头，根据国家同步辐射实验室基于可调谐红外激光的能源化学研究大型实验装置FELiChEM的束流特点，在CST内对所设计的探头进行束流模拟仿真。仿真结果表明，该耦合器可以实现对特定模式的耦合，并有效降低其它模式的干扰，采用同轴滤波耦合结构和膜片加载波导滤波结构的谐振腔监测器可以实现对FELiChEM装置束团长度的高精度测量，测量误差小于2 %。

为了研究储存环束流多束团纵向运动特性，在合肥光源（HLS-II）上研制了一套逐束团相位测量系统。该系统利用示波器直接采集BPM和信号，采用过零点检测法、时间差分（Temporal Difference, TD）法相结合的方法从BPM和信号中提取出逐束团相位。介绍了逐束团相位测量系统的系统构架、相位提取方法以及在HLS-II上的一些实验结果。通过对该系统记录的5 ms时间长度的逐束团多圈相位数据的离线分析，得到多束团纵向运动的同步振荡的频率、纵向工作点、束团振荡的模式信息以及振荡模式增长率等特征信息，诊断出HLS-II在top-off恒流运行期间存在2个较强的纵向耦合束团不稳定模式，并提取出了2个振荡模式的增长率。该系统的逐束团相位测量结果及相关纵向不稳定性分析可为机器研究、纵向反馈系统调试评估及高频RF系统的性能评估等提供参考。