Intense spontaneous violet emission due to coherent two-photon excitation in potassium
N. Tan-no, Ken-ichi Kan’no, Kenichi Yokoto, Humio Inaba · IEEE Journal of Quantum Electronics · 1973
This paper describes the measured result of intense violet emission at 4048 Å that is due to the strong coherent two-photon excitation in potassium vapor. Anomalous delay and narrowing of the emitted pulse was observed in contrast to the incident pulse. The intensity dependence on the atomic density also is reported.