亚毫米波频段的法布里-珀罗谐振器仿真

Simulation of Fabry-Perot Resonator at Millimeter Wave Frequency

通过对法布里-珀罗谐振器的理论分析,说明这种谐振器的基模电磁场分布具有"高斯光束"的形式,在其束腰位置近似为横电磁波,在亚毫米波频段应用于研究超导交流约瑟夫森效应具有优势。应用CST Microwave Studio 2006对其进行仿真,验证了上述特点并得到谐振模式,谐振器反射镜尺寸,反射镜曲率以及耦合方式对工作状态的影响。适当调整以上参数,可以优化腔内能量的聚集度,从而使谐振器很好地应用于观测约瑟夫森结的夏皮罗台阶。

The theoretical analysis to the Fabry-Perot resonator indicates that the field distribution of the fundamental mode of the resonator is in the form of ＂Gaussian beam＂. The electromagnetic field at the waist of the beam is quasi TEM, which demonstrates the advantages of such resonator applied to the study on the AC Josephson effect of the superconductor at sub-mm wave frequency. The characteristics of the electromagnetic field were testified, and the influences of a number of factors including resonant modes, dimension of the resonator and curvature of the reflector as well as coupling methods on the operating status of the resonator were obtained by means of CST Microwave Studio 2006. With adjusted foregoing parameters, the extent of the energy convergence in the cavity can be optimum and therefore the resonator can be well applied in the observation of the Shapiro steps of the Josephson junctions.