Frequency stability and stabilization of a chemical laser

We have built a low-power CW HF/DF chemical laser, designed to achieve high-frequency stability. Measurements are reported which characterize the instantaneous spectral width of the laser output to less than one part in 1011(Δν < 1kHz) and the variations in absolute frequency of this emission with time to four parts in 1010(Δν = ±20kHz) per 0.1 ms. Two experiments to actively stabilize the laser frequency are reported. In one experiment the laser was locked to a high-finesse Fabry-Perot to five parts in 109(Δν = ±250kHz) for many minutes. In the other experiment one laser was locked to another using heterodyne beat spectroscopy to 1.7 parts in 109(Δν = ±85kHz). The stabilization experiments were limited by the feedback loops used.