中物院1~4.2 THz FEL装置波导谐振腔优化设计  

Waveguide optical resonator optimization of CAEP THz-FEL in 1−4.2 THz

作　　者：窦玉焕[1] 束小建[1] 吴岱[2] 徐勇[2] 杨兴繁[2] 黎明[2] Dou Yuhuan;Shu Xiaojian;Wu Dai;Xu Yong;Yang Xingfan;Li Ming(Institute of Applied Physics and Computational Mathematics,P.O.Box 8009,Beijing 100094,China;Institute of Applied Electronics,CAEP,Mianyang 621900,China)

机构地区：[1]北京应用物理与计算数学研究所,北京100094 [2]中国工程物理研究院应用电子学研究所,四川绵阳621900

出　　处：《强激光与粒子束》2022年第3期70-74,共5页High Power Laser and Particle Beams

基　　金：中国工程物理研究院基金项目(2015B0402091);北京应用物理与计算数学研究所所长基金项目(ZYSZ1518-09);国家重大科学仪器设备开发和应用专项基金项目(2011YQ1300180102)。

摘　　要：针对中物院高功率太赫兹自由电子激光(THz FEL)装置,结合FEL光腔振荡器实验的实际情况,提出了全波导近共心谐振腔设计方案。完成了THz波段波导光腔对光腔品质影响的理论分析和模拟计算,确定了波导设计尺寸为14 mm和22 mm。同时针对最初实验调试过程中无法出光饱和的问题,提出将波导更换为22 mm大尺寸波导的建议,波导更换后很快在2.56 THz获得饱和出光。另外针对实验频段无法覆盖到1~2 THz的问题,我们通过波导内壁粗糙度进行分析判断,提出采用14 mm铜材质的全波导FEL振荡器的设计方案,采用该方案后,实验成功将辐射频段拓展到0.7~4.2 THz,获得饱和输出。Investigations of waveguide application to the whole optical cavity of CAEP’s high power THz-FEL device are achieved.The influence of waveguide on the quality of optical cavity is calculated by theoretic analysis and simulations.The waveguide gae size is designed to be 14 mm and 22 mm.In the experiment,we found it was have to get lasing in 1−2 THz.By analysis,we think the reason is that waveguide is made of Titanium and the waveguide wall roughness is unsuitable,which induce large diffraction loss of optical resonator.To reduce the loss,we use a new waveguide made of Cu to replace the old one.Using the new waveguide,lasing and saturation were attained in 1−2 THz in 2019.Then the whole facility counld run stably in 0.7−4.2 THz using the 14 mm Cu wave-guide.

关 键 词：自由电子激光 太赫兹 光腔 波导 理论设计 

分 类 号：TN248.6[电子电信—物理电子学]