Doppler-free adiabatic self-induced transparency

In this paper, we present a novel approach for Doppler-free transparency in a 2L system. This technique, named adiabatic self-induced transparency (ASIT), resembles a double-STIRAP process in a 3L system. ASIT consists in driving the 2L system with a laser pulse whose detuning with respect to the atomic transition and whose field amplitude are temporally varied in a proper shape. We have studied the robustness of the reported ASIT phenomena against modifications of the pulse parameters. We also discuss a possible experimental implementation of ASIT using 87Rb atoms.