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

Hidehiro Asai, Shiro Kawabata

(Submitted on 11 May 2017)

https://arxiv.org/abs/1705.04129

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.

Abstract-Emission of Circularly Polarized Terahertz Wave from Inhomogeneous Intrinsic Josephson Junctions

Hidehiro Asai,  Shiro Kawabata
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?reload=true&arnumber=7377043

We have theoretically demonstrated the emission of circularly-polarized terahertz (THz) waves from intrinsic Josephson junctions (IJJs) which is locally heated by an external heat source such as the laser irradiation. We focus on a mesastructured IJJ whose geometry is slightly deviate from a square and find that the local heating make it possible to emit circularlypolarized THz waves. In this mesa, the inhomogeneity of critical current density induced by the local heating excites the electromagnetic cavity modes TM (1,0) and TM (0,1), whose polarizations are orthogonal to each other. The mixture of these modes results in the generation of circularly-polarized THz waves. We also show that the circular polarization dramatically changes with the applied voltage. The emitter based on IJJs can emit circularly-polarized and continuum THz waves by the local heating, and will be useful for various technological application.