Low-cost method for stabilization of a CO2 laser for use in far infrared laser pumping

A simple and inexpensive technique for stabilization of a CO2 laser used to optically pump a far infrared waveguide laser is discussed. The technique uses the fact that the output power of the CO2 laser varies as the output frequency is swept through the Doppler profile of the emission line. Stabilization is obtained by adjusting the mirror separation and forcing the output power to remain constant at the level corresponding to the desired pump frequency.