Page 168 - Tunable Lasers Handbook

4 CO, Isotope Lasers and Their Applications 1

TABLE 14 Small-Signal Gain Coefficients cxo and Saturation Parameters Z, for a
-
3He--1,C160,--1JN,-Xe - Mixture0
Band mansition a. (7% cm-1 or m-1) I, (W-cm-2) aOIs (W-cm-3)
P(28) 0.90 32 0.28
P(2JJ 1.01 34 0 34
P(20) 1.07 17 3.50
P( 16) 1 .oo 12 0.32
P(12) 0 88 38 0.34
1
R(12) 0.88 24 0.21
R( 16) 0 96 29 0.28
R(20) 0.96 29 0.28
R(23) 0.88 33 0.29
R(28) 0 77 26 0.20

P(28 ) 0.79 22 0.18
P(23) 0.88 22 0.20
P201 0.90 25 0.23
P:16j 0.87 22 0.19
Pi121 0.73 20 0.15
11
R(12) 0.71 22 0.16
R(16) 0.84 23 0.19
R(20: 0.84 23 0.19
R(2-l) 0.85 22 0.19
R(28) 0.70 20 0.14
OReprinted with permission of Freed era/. [125]. 0 1982 IEEE.

trying to maximize the power output of an oscillator with the same discharge
tube diameter. CO, laser oscillators, which are usually optimized for maximum
power output. operate under highly saturated conditions. The saturation parame-
ter is generally proportional to pressure squared [ 127],Zs ~p', and therefore C02
laser oscillators are filled to higher pressures than amplifiers, which are usually
optimized for maximum small-signal gain.
Our measurements of the small gain coefficients and saturation parameters
for 20 transitions in each of the five high-purity isotopic species-Wl GO,,
W180,. 13C16O,, 13C180,. and 14C1607-are summarized in Tables 11 through
18. The large variations measured for corresponding I and I1 band transitions of
a given isotope were due to the Fermi-resonance coupling of the (1000) and