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Updated: Jun 20, 2026

Characterizing Far-infrared Laser Emissions and the Measurement of Their Frequencies
Published on: December 18, 2015
Spectroscopy of (12)CF(4) features near the 9-microm (12)C(16)O(2) R(10), R(12), and R(18) lines by CO(2)-laser and
Abstract:
The (12)CF(4) molecule has been made to lase at various wavelengths in the 16-microm v(4) + V(2) ? V(2) band by pumping in the 9-microm 0 ? V(2) + V(4) band with (12)C(16)O(2) lines. The strongest reported (12)CF(4) laser line occurs at 615.06 cm(-1) and is pumped by 9R12 [9-microm band, R(12) line]. We have measured, by two techniques, the absorption of (12)CF(4) in 9R12, and also in 9R10 and 9R18, which are known to result in weak 16-microm laser transitions. This was done both at room temperature and at an estimated 100 K, and striking changes in spectral features were noted as the temperature was lowered. For the 9R12 laser line, we find a (12)CF(4) feature located 30 +/- 3 MHz to the high-frequency side of line center, with a peak absorption coefficient of 5 x 10(-4) to 9 x 10(-4) cm(-1) Torr(-1), depending on temperature. By contrast, there are only weak (12)CF(4) features within +/-40 MHz of the 9R10 and 9R18 laser-line centers, and the absorption coefficients of those features are 1 x 10(-4) to 2 x 10(-4) cm(-1) Torr(-1).
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