Page 166 - Tunable Lasers Handbook

4 CO, Isotope lasers and Their Applications 14

where the coefficients a and b were calculated from tabulated [ 1241 unperturbed
energy-le\;el splittings 6 and the energy-level splittings A. including Fermi reso-
nance effects. as
I,
a = [(A + 6) / ?A]' '; b = (I - a') -. (21)

-
Table 12 summarizes the results Silver et al. obtained [123] for 12C160i,
12C18O,, and 13C160,.
In ;heir 1970 paier, Silver et al. [ 1231 gave results only for the ratios of the
measured P(20) gain values but not for the individual gain coefficients. More
comprehensive experiments were carried out at MIT Lincoln Laboratory by
Freed et al. in 1981 in which both the small-signal gain coefficients a. and the
saturation parameters I, were determined [125] for five laser transitions in each
of the four rotational branches of the (0001-1) and (0001-11) vibrational bands.
Some of the results associated with the P(20) transitions are listed in Table 13

TABLE 1 2 Results of Silver et a/. [ 1231

Gain coefficient

TABLE 13 Comparison of the Small-Signal Gain Coefficients and Saturation
Parameters of the P(20) Transitions in Five CO, Species0

I Calculated - 1.3 0.5 3.2 1 .o 7.1
K-I
K-I1

OReprinted with permission from Freed et al. [125]. 0 1982 IEEE.