Emission of simultaneous tunable off-resonance and line centre FIR Raman lines in NH3 and CH3F

Abstract By pumping with a continuously tunable CO 2 laser we have analysed the FIR emission of the sR(3,0) ammonia line and the λ =2 mm emission of the R (1) CH 3 F absorption line. The simultaneous emission of an off-resonance tunable Raman frequency and an untuned line centre one has been observed. The results agree with the theory. In addition about 8% tuning of the mean FIR frequency was observed at 150 GHz.