Absolute two-photon excitation cross-sections in NOA technique has been developed which allows the determination of a two-photon absorption cross-section to be made relative to the Raman scattering cross-section in nitrogen. Spatial and temporal effects associated with the lasers are ratioed out to give a result independent of laser parameters. The necessary theory to extract a cross-section from the measured ratio of a Coherent Anti-Stokes Raman Scattering (CARS) signal in N2 to a four-wave mixing signal in NO has been developed. The technique has been demonstrated on the R(22) + S(12) (J-double-prime = 9 1/2) line in NO and a cross-section of (2.9 + or - 1.8) x 10 to the -49th (cm to the 4th power)-s was determined. This technique appears to be applicable to a number of other diatomic molecules.
Document ID
19840060122
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Burris, J. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Mcgee, T. (NASA Goddard Space Flight Center Laboratory for Planetary Atmospheres, Greenbelt, MD, United States)
Mcilrath, T. (Maryland, University College Park, MD, United States)