Optics Letters
Line narrowing and hole burning within the homogeneous linewidth: a new wave-mixing effect in two-level systems
Jens Förstner, A. Knorr, Markus Lindberg, S. W. Koch
Abstract
The interaction of strong low-area pulses with two-level systems shows absorption line narrowing and hole burning within the homogeneous linewidth as a result of nonlinear wave mixing. The wave mixing results from the two-level electronic saturation nonlinearity and occurs, depending on the sign of the pulse area, as a strong absorption enhancement or gain at the transition frequency of the two-level system for resonant excitation.