Small-signal gain and saturation parameter of a transverse-flow CW oxygen-iodine laser

The small-signal gain and saturation parameter of a transverse-flow CW oxygen-iodine laser have been experimentally obtained for the first time from output power measurements made as a function of the cavity losses without using a CW probe laser. These measurements typically yield
\alpha_{0} \simeq 0.045
m
^-1
and
I_{s} \simeq 0.44
kW/cm
²
for a Cl
2
flow rate of
1.4 \times 10^{-3}
mol/s with an I
2
flow rate of
4 \times 10^{-6}
mol/s. The dependences of the small-signal gain and saturation parameter have been also found on the Cl
2
flow rate. These behaviors are qualitatively explained by a simple two-level model.