Frequency stability associated with a cw HF laser

The frequency stability of a cw, electrically initiated HF mixing laser was investigated using heterodyne and interferometric techniques. A stability corresponding to 1 part in 10(8) was achieved over an observation time of 150 msec. The data indicated that improved performance would be achieved by increasing the mechanical stability in the optical system. Long-term stability was demonstrated by locking the laser output to the Lamb dip of the lasing transition. Based upon these experiments, the cw chemical laser shows potential as a stable frequency local oscillator for applications such as laser radar and communications.