Exceeding the Manley-Rowe quantum efficiency limit in an optically pumped THz amplifier

摘要

Using a microscopic theory based on the Maxwell-semiconductor Blochequations, we investigate the possibility of an optically-assistedelectrically-driven THz quantum cascade laser. Whereas in optical conversionschemes the power conversion efficiency is limited by the Manley-Rowe relation,the proposed optically-assisted scheme can achieve higher efficiency bycoherently recovering the optical pump energy. Furthermore, due to quantumcoherence effects the detrimental effects of scattering are mitigated.