Four-wave parametric oscillation in sodium vapor by electromagnetically induced diffraction.

@article{Harada2007FourwavePO,
  title={Four-wave parametric oscillation in sodium vapor by electromagnetically induced diffraction.},
  author={Ken-ichi Harada and Minoru Ogata and Masaharu Mitsunaga},
  journal={Optics letters},
  year={2007},
  volume={32 9},
  pages={1111-3}
}
We have observed a novel type of parametric oscillation in sodium atomic vapor where four off-axis signal waves simultaneously build up under resonant and counterpropagating pump beams with elliptical beam profiles. The four waves, two of them Stokes shifted and the other two anti-Stokes shifted, have similar output powers of up to 10 mW with a conversion efficiency of 30% and are parametrically coupled by electromagnetically induced diffraction.