Engineering the Cavity modes and Polarization in Integrated Superconducting Coherent Terahertz Emitters

On-chip, solid-state terahertz (THz) devices based on superconducting Bi2Sr2CaCu2O8+δ(BSCCO) can coherently and continuously radiate electromagnetic waves with frequencies tunable between 100 GHz and 11 THz. Their huge frequency tunability observable by the application of an applied voltage of as small as $0 < V_{\mathrm{d}\mathrm{c}}(\mathrm{V}) < 1.5$ covers the entire THz gap. Here, we report on a novel approach towards engineering the THz waves in such devices, with pentagonal cavities, by performing the numerical simulations/analytical calculations of the cavity resonances. We investigate the radiation of the intense and coherent THz waves in pentagonal emitters by keeping the bias feed point in the middle and changing the device geometry. We compare the results with the experiment and find a good agreement.