Abstract

Because of the interest in CO₂ isotopes for laser applications involving atmospheric propagation, we have determined the small signal gain for ¹³CO₂ and compared the results with measurements for ¹²CO₂ under identical pumping conditions. Previous work with low pressure cw lasers found that the small signal gain for ¹³CO₂ was ≈60% of that for ¹²CO₂.⁽¹⁾ Small signal gain measurements have not been reported for high pressures, but similar energies have been obtained from a TEA laser using both ¹³CO₂ and ¹²CO₂ gas mixes.⁽²⁾ Absorption measurements indicate that the 00°1 - (10°0 + 02°0)_I transition probability is higher for ¹³CO₂,⁽³⁾ which would result in higher small signal gain, if the inversion density is the same. Because of this conflicting information, it is difficult to design an amplifier operating with ¹³CO₂. Therefore, we have measured the small signal gain for both ¹³CO₂ and ¹²CO₂ for the same pumping conditions.

© 1987 Optical Society of America