Dynamics of the optically pumped midinfrared NH/sub 3/ laser at high pump power. I. Inversion gain. II. Raman gain and a-c Stark shifts

Journal Article · Sat Sep 01 04:00:00 EDT 1984 · IEEE J. Quant. Electron.; (United States)

DOI:https://doi.org/10.1109/JQE.1984.1072514· OSTI ID:6062719

Morrison, H D; Garside, B K; Reid, J

The present rate equation model for the major features of gain dynamics in pulsed NH3 lasers operating with buffer gases is validated through detailed comparison with measured gain coefficients for two different pumping transitions, and is found to accurately predict gain distributions as a function of rotational quantum number. The model envisages the absence of vibrational energy transfer between ortho-NH3 and para-NH3, and assumes rapid thermalization of the rotational populations. The parameters determining the effectiveness of buffer gases are also identified. While N2 and Ar are found to be effective buffer gases, He is noted to be far less effective. In addition, two different Raman transitions are observed in an investigation of coherent effects produced by high-intensity pumping on aR(6, 0) in NH3 for both the pure gas and for mixtures with an inert buffer gas. One is the usual directly pumped Raman transition, while the other transition is pumped indirectly since it first requires a large population transfer to the upper vibrational level. Raman gain coefficients of 10 percent/cm and inversion gain coefficients exceeding 2 percent/cm are observed, and compared to a combined density-matrix and rate-equation model. 54 references.

• Research Organization: McMaster Univ., Hamilton, Ontario
• OSTI ID: 6062719
• Journal Information: IEEE J. Quant. Electron.; (United States), Journal Name: IEEE J. Quant. Electron.; (United States) Vol. QE-20; ISSN IEJQA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420300* -- Engineering-- Lasers-- (-1989)
AMMONIA
AMPLIFICATION
EMISSION SPECTRA
GAIN
GAS LASERS
HYDRIDES
HYDROGEN COMPOUNDS
LASERS
MATHEMATICAL MODELS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
POPULATION INVERSION
RELAXATION TIME
SPECTRA