Control of Circularly Polarized THz Wave from Intrinsic Josephson Junctions by Local Heating

This paper reports a practical method of generating circularly polarized terahertz (THz) waves from intrinsic Josephson junctions (IJJs) and controlling their polarization states by external local heating. We theoretically find that a mesa-structure IJJ whose geometry is almost square can emit circularly polarized THz waves by local heating of the mesa. Moreover, we demonstrate that the polarization states of the THz waves change dramatically with the local heating position. Our results indicate that the use of local heating can provide a high level of controllability of the THz emissions and significantly extend the range of applications of IJJ-based THz emitters.