Cw carbon monoxide laser with microwave excitation in the supersonic flow

Abstract

A new technique of efficiently coupling microwave energy into a supersonic gas flow is described. A stable self-sustained 2.45-GHz microwave discharge is applied to excite a cw CO gasdynamic laser. Electron densities well above the cutoff value have been achieved together with a reduced field strength within the discharge that is appropriate for efficient vibrational excitation. With an energy loading of 0.15 eV/molecule CO a laser power of 285 W was obtained in a small-scale flow channel at an overall efficiency of 6%.