Full-wave multiphysics model for simulation and investigation of terahertz photoconductive antenna using LUMERICAL and CST softwares

Abstract

In this work, the physical mechanism of the full-wave multiphysics model is described underlying the simulation of terahertz photoconductive antenna (PCA) using hybrid softwares incorporating LUMERICAL and CST. The feature of this simulation is that the multiphysical phenomena that occur in the PCA, such as light-matter interaction, photoexcited carriers, and full-wave propagation, are considered and embodied in the simulation. The accuracy of the presented simulation framework is verified by comparing its results with some commercial softwares such as COMSOL, SILVACO, and the numerical of three-dimensional finite difference time domain (3-D FDTD) method.Themethod. The maximum discrepancy of the simulation results between this hybrid software framework and others is less than 2%, which indicates the accuracy of these simulation results. In addition, this hybrid simulation framework can be used to characterize the parameter-dependent performance of a PCA. The obtained results are used as a guideline to present modified PCAs where a nanostructure is added inside the antenna gap to enhance the PCA performance. The two modified PCAs are defined as nano-line and nano-crossline PCAs, where nano-lines are connected to one or both contacts. The conversion efficiencies of the nano-line and nano-crossline PCAs are enhanced by 28.5 and 64 times, respectively, with respect to conventional PCA.