Experimental Study of an Efficient, High Power and Tunable Continuous-Wave CO2 Laser

The tunable CO2 laser is a common pump source for optically pumped terahertz lasers. In this paper, based on a sealed-off CO2 laser tube and a grating-tuned cavity, we reported an efficient, high-power, low-cost, simple structure and tunable continuous-wave CO2 laser. A sealed-off CO2 laser tube was designed and customized, and its plasma discharge characteristics were experimentally analyzed. The influence of output coupler transmittance and discharge current on the laser’s tunability and output power was systematically studied using grating tuning. A total of 78 spectral lines were achieved within the wavelength range of 9.17–10.86 μm. The maximum output power of 55.5 W was recorded on the 10P20 line when the output coupler transmittance was approximately 22%. The laser exhibited a beam spot radius of about 3.8 mm and a beam quality factor (M2) of 1.74.