• DOI:10.1103/PhysRevA.97.063421
• Corpus ID: 118827980

Ab initio calculations of the linear and nonlinear susceptibilities of N2 , O2 , and air in midinfrared laser pulses

@article{Brown2018AbI,
  title={Ab initio
 calculations of the linear and nonlinear susceptibilities of 
N2
, 
O2
, and air in midinfrared laser pulses},
  author={Jeffrey M. Brown and Arnaud Couairon and Mette B. Gaarde},
  journal={Physical Review A},
  year={2018}
}

• Jeffrey M. Brown, A. Couairon, M. Gaarde
• Published 10 April 2018
• Physics
• Physical Review A

We present first-principles calculations of the linear and nonlinear susceptibilities of N$_2$, O$_2$, and air in the mid-infrared wavelength regime, from $1-4$ $\mu$m. We extract the frequency-dependent susceptibilities from the full time-dependent dipole moment that is calculated using time-dependent density functional theory. We find good agreement with curves derived from experimental results for the linear susceptibility, and with measurements for the nonlinear susceptibility up to 2.4 $\mu$m. We also find that the susceptibilities are insensitive to the laser intensity even in the strong field regime up to $5\times 10^{13}$ W/cm$^2$. Our results will allow accurate calculations of the long-distance propagation of intense MIR laser pulses in air.