Experimental researches and theoretical numerical computer simulations of spectrum of rubidium atoms in the strong femtosecond field were made. Pumping of focused radiation by train of 100-femtosecond pulses (comb) near resonance transition (780 nm) leads to the appearance of unidirectional coherent radiance in the near IR and in the blue area. Numerical simulation confirms the role of the nonlinear interference (coherent) effect.
Korshok, I. K., Borisov, E. N., Pulkin, S. A., Kalinichev, A. A., Pulkin, N. S., & Uvarova, S. V. (2018). Unidirection coherent radiation in Rb-atoms driving by strong femtosecond comb. In Proceedings - International Conference Laser Optics 2018, ICLO 2018 (p. 342). Institute of Electrical and Electronics Engineers Inc. https://doi.org/10.1109/LO.2018.8435230