Carreño Sánchez, FernandoAntón Revilla, Miguel Ángel2023-06-202023-06-202010-12-010030-401810.1016/j.optcom.2010.07.024https://hdl.handle.net/20.500.14352/42814Received 9 March 2010, Revised 28 May 2010, Accepted 1 July 2010, Available online 24 July 2010.We analyze the storage and retrieval of a weak light pulse, having two orthogonally (circularly) polarized components, onto an atomic ensemble of four-level atoms of the tripod type driven by a far detuned coupling field. The atoms are subject to a longitudinal magnetic field which produces a spatially varying Zeeman splitting of the lower levels along the medium and allows for a spatial encoding of the different angular frequencies of the input pulse during the storage phase. A single reversion of the external magnetic field results in a rephasing of the dipoles and leads to the release of the stored signals. The shape of the recovered pulse is a time-reversal copy of the input pulse. The application of an additional reversion of the magnetic field during the storage phase allows the release of a copy of the input pulse without time reversal. We also show that the system may operate like an all-optical multiplexer when considering two impinging optical fields which have orthogonal components. The proposal has potential applications in quantum information processing.engjournal articlehttps://doi.org/10.1016/j.optcom.2010.07.024https://www.sciencedirect.com/science/article/pii/S0030401810007601restricted access535.31535.5Coherent optical effectsOptical memoryOptical echoesÓptica (Física)Óptica geométrica e instrumental2209.19 Óptica Física2209.06 Óptica geométrica