A microwave excited high power CO laser operating at room temperature
is described. Maximal output power of 240 W, or 800 W/m with an extrac
tion efficiency of 8% is achieved using a 30 cm long microwave dischar
ge. The laser gas mixture (CO:N2:He:Xe: O2 = 8.5:7.5:79.1:4.5:0.4 (%))
recirculates in a closed loop through the discharge tube with a rate
of typically 2000 m3/h at a pressure of 4 kPa. The laser gas is cooled
down to an inlet temperature of 18-degrees-C by water operated heat e
xchangers. Results from this work demonstrate the possibility of high
power operation of a CO laser at room temperature. Improvements both i
n the extraction efficiency and the output power appear possible by in
creasing the microwave power input.