We theoretically investigate the effect of the atomic densities N on propagation and spectral property of femtosecond chirped Gaussian pulse in a three-level Λ-type atomic medium by using the numerical solution of the full Maxwell- Bloch equations. It is shown that, when the positive chirped pulse with area 3π, propagate in the medium with smaller N, pulse splitting doesn’t occur and many small oscillations at the trailing edge of the pulse appear, in addition, the level |2< population ρ₂₂ of the pulse exhibits an oscillation feature with time evolution, moreover, the spectral component near the central frequency of the pulse shows an oscillation characteristic too, and the propagation and spectral property of the negative chirped 3π pulse is very similar to that of the positive chirped 3π pulse. For the positive chirped 3π pulse pulses, propagate in the medium with larger N, pulse splitting also doesn’t occur but many small oscillations both at leading edge and the trailing edge of the pulse appear, and the population ρ₂₂ of the pulse only exhibits an scarcely oscillation feature with time evolution, at the same time many oscillations both in blue shift and red shift components of the pulse appear but the spectral component near the central frequency of the pulse oscillate more severely, and the propagation and spectral property of the negative chirped 3π pulse is very similar to that of the positive chirped 3π pulse, but comparing with the case of the negative chirped 3π pulse, the propagation of the positive chirped 3π pulse is delayed at the same distance and the delayed time becomes longer with the distance increasing.

Date Published: 4 May 2015
PDF: 7 pages
Proc. SPIE 9543, Third International Symposium on Laser Interaction with Matter, 95431U (4 May 2015); doi: 10.1117/12.2181717

Published in SPIE Proceedings Vol. 9543:
Third International Symposium on Laser Interaction with Matter
Yury M. Andreev; Zunqi Lin III; Xiaowu Ni; Xisheng Ye, Editor(s)