Nonlinear rovibrational response in the propagation of long-wavelength infrared pulses and pulse trains

The propagation of long-wavelength pulses is affected by a multitude of near-resonant rovibrational transitions in atmospheric constituents, of which water vapor is generally the most abundant. We extract the pure nonlinear response of these transitions from a high-resolution transmission-based effective model, which is additive to the spectrally resolved linear response, and study the influence of this on the propagation of laser pulses and pulse trains. Compared to simulations with only electronic Kerr self-focusing, we find that the nonlinear rovibrational response introduces an additional modification to strongly self-focused laser pulses and stark changes to pulses that are close to the self-focusing threshold.