Pulsed CO₂ Laser Pumped by a Longitudinal Discharge in an Alternating Magnetic Field

An original technique is suggested for pumping a pulsed CO₂ laser by a longitudinal discharge in an alternating magnetic field. A small CO₂ laser with active medium ∼200 mm long, pulse energy of ∼30 mJ, and efficiency of 3.4% is designed on the basis of this technique. It is revealed that the main factor which limits the generation energy of small lasers is the development of current instabilities in a longitudinal discharge over a cross section of the discharge tube. It is noted that the growth of the instabilities accelerates as the pressure of a CO₂ : N₂ : H₂ : He gas mixture increases to more than 0.1 atm and the specific pump power becomes higher than 3 MW/cm³. The use of an external alternating magnetic field superimposed on a pulsed longitudinal discharge makes it possible to increase the total pressure of the gas mixture in the laser to 0.4 atm when maintaining the combustion of the volume discharge.