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Updated: Jun 19, 2026

Characterizing Far-infrared Laser Emissions and the Measurement of Their Frequencies
Published on: December 18, 2015
Far-infrared emission from an optically pumped overtone Raman CH(3)I laser
Abstract:
We report what is to our knowledge the first generation of far-infrared laser radiation by stimulated Raman scattering resonantly enhanced by an overtone vibrational-rotational transition. Using a frequency-tunable high-pressure CO(2) laser as the pump source, we obtained laser emission in the frequency range from 12 to 27 cm(-1) by optical pumping of gaseous CH(3)I near resonant vibrational-rotational transitions of the 2v(3) overtone and the v(6) fundamental band. Overtone Raman transitions involving the nondegenerate v(3) vibration were found to show higher efficiency than Raman transitions within the fundamental band of the twofold-degenerated v(6) vibration. From the studies of the temporal behavior of the far-infrared laser emission, we estimate a bandwidth of approximately 200 MHz for the Raman gain regions for both the 2v(3) overtone and the v(6) fundamental transitions.
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