New Ideas for Efficient Generation of Coherent Near-Millimeter Wave Radiation

Production of efficient sources of coherent near millimeter wave (NMMW) radiation is an important unsolved prohlem. In the most efficient devices at present, optically pumped lasers and gas-discharge systems such as the HCN laser, excitation supplied at energy \hslash \omega ∼ leV produces NMMW photons of energy \hslash \omega ∼ 1−2 ev, the remainder of the excitation energy being trapped in the molecule. This leads to an intrinsic reduction ξ o = \Omega/ \omega ∼ 10−2 in power conversion efficiency, since in these systems, each excitation quantum yields at best one NMMW photon.