Acta Photonica Sinica, Volume. 36, Issue 12, 2360(2007)
Studies of Lasing Without or with Inversion in Open Four-Level Atomic System
The model of an open four-level atomic system is presented on the basis of the closed four-level atomic system. In the rotating wave, slowly varying envelope and mean field approximations, the density-matrix motion equations of the system are solved, and the linear analytical solution in the steady state is obtained. The numerical calculation from the steady-state solution of the open system is presented. It is shown that a change from LWI to lasing with inversion action can occur due to the Rabi frequency of the driving field increasing; another change from lasing with inversion to LWI action can also occur as the exit rate or ratio of injection rates increases; high refractive index without absorption can be obtained; the curve of ρ33 -ρ11 (vs △2) presents the shape of the rectangle wave.
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[in Chinese], [in Chinese], [in Chinese], [in Chinese]. Studies of Lasing Without or with Inversion in Open Four-Level Atomic System[J]. Acta Photonica Sinica, 2007, 36(12): 2360