Theoretical gain spectrum of far-infrared Raman lasers

The four-level density matrix theory of the Raman FIR laser is extended to include arbitrary pump and emission field strengths and arbitrary pump frequency offsets from resonance. The results accommodate the full range of spectral variation that is observed when CH/sub 3/F Raman FIR lasers are operated at widely differing values of the rotational quantum number J. The extended theory is also useful for optimizing the temperature and pressure of these broadly tunable lasers to achieve maximum spectral coverage.<
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