Development of CO2 laser excited by 2.45-GHz microwave discharge

A new technique to excite a CO 2 laser by 2.45GHz microwave discharge is developed. Microwave plasma produced by the technique is so stable and homogeneous that any additional means to effectuate laser action such as fast circulation of laser gas and external magnetic field are not necessary. Utilizing the technique, a compact diffusion cooled CO 2 laser with 40cm active length is constructed. A magnetron available for microwave ovens is used as the power source of the laser. Average output power of 116W and maximum conversion efficiency of 18% in CW mode, peak output power of 1.2kW in pulse mode are obtained. Output beam with good focusibility is extracted by applying an unstable-waveguide hybrid resonator.