Storage and retrieval of vector optical solitons via double electromagnetically induced transparency

We propose a scheme to realize storage and retrieval of two-component optical soliton in a coherent atomic system. The system under consideration is a cold, lifetime-broadened four-level atomic gas with a tripod configuration working at the condition of double electromagnetically induced transparency. We show that due to the existence of two dark states, the optical absorption of the probe pulse can be largely reduced. In addition, the two orthogonal polarization components of the probe pulse with a form of vector optical soliton cannot only be slowed down substantially but also be stored and retrieved robustly by switching a control laser field off and on. We also show that it is possible to achieve a memory of N-component optical soliton by using the N dark states in a (N + 1)-pod system (N > 2). The results reported here may have promise in applications for light information processing in a weak nonlinear regime.