Investigation of the dependence of degenerate four-wave mixing line intensities on transition dipole moment

Abstract

We report an investigation of the dependence on transition dipole moment of isolated line intensities in degenerate four-wave mixing in the A2Σ+ (υ′ = 0) ← X2Π (υ″ = 0) band for NO. For spectrally integrated intensities we found that the dependence was well described by a power law μx, where μ is the one-photon transition dipole moment. As a result of saturation, the exponent x depends on laser intensity. The observations are in reasonable agreement with a simple two-level model [ Opt. Lett.294 ( 1978);Opt. Lett.3, 205 ( 1978)], which predicts limiting dependences of μ8 and μ3 for low and high intensities, respectively. At intermediate laser intensities the model is consistent with an observed rapid decrease in the exponent with increasing laser intensity, followed by a plateau extending to high intensities.