Continuous-wave CH3F waveguide laser at 496 µm: Theory and experiment

The kinetic processes controlling the conversion of CO
2
pump radiation into far-infrared (FIR) radiation in optically pumped waveguide lasers are discussed. It is found that pump saturation and excited-state FIR absorption play major roles in limiting the conversion. Good agreement between theory and experiment was obtained over a wide range of pump powers, gas pressures, and mirror reflectivities. For a well-optimized system, power-conversion efficiencies of 0.2-0.6 percent can be realistically achieved for CH
3
F.