Terahertz quantum cascade lasers with silver- and gold-based waveguidesR.A. Khabibullin, N.V. Shchavruk, D.S. Ponomarev, D.V. Ushakov, A.A. Afonenko, O.Yu. Volkov, V.V. Pavlovskiy and A.A. DubinovEPJ Web Conf., 195 (2018) 04002DOI: https://doi.org/10.1051/epjconf/201819504002