Small signal gain and saturation intensity of 00° 1-[10°0, 02°0]I and IIvibrational band transitions in sealed-off CO2isotope lasers

Effects due to Fermi resonance play a major role in determining the very significant variations of gain in the various CO
2
isotopes. We have measured the small signal gain coefficients and saturation parameters for five transitions (
J= 12, 16, 20, 24, 28
) in each of the four rotational branches of the
00\deg 1-[10\deg0, 02\deg0]
I and II
vibrational bands using sealed-off TEM
ooq
mode oscillators and amplifiers. Isotopic species of pure
¹²
C
¹⁶
O
2
,
¹²
C
¹⁸
O
2
,
¹³
C
¹⁶
O
2
,
¹³
C
¹⁸
O
2
, and
¹⁴
C
¹⁶
O
2
were measured with
⁴
He-
¹⁴
N
2
-Xe gas additives under identical conditions. Substitutions of either
¹⁵
N
2
or
¹³
C
¹⁶
O instead of
¹⁴
N
2
were also tried. The results obtained may serve as guidelines in the design of sealed-off CO
2
lasers and amplifiers.