Spatial-frequency Routing Of Image Via Atomic Spin Coherence

In the era of information explosion, in order to meet the requirement for information transmission and information processing, the study of quantum information is becoming more and more widely. Soon after, people will have the quantum information network era. A future quantum information network would consist of some separated devices, in which quantum information can be stored and manipulated in a controlled fashion. Coherent interactions between light and matter provide powerful tools to obtain the above goal. In many information processing,Coherent and all-optical manipulation of image plays a significant role in many fields, including holography, classic and quantum correlations, image and information processing. Most experiments of EIT-based light-storage deal with the amplitude and phase variation of the probe pulse in the time domain, and pay little attention to the transverse spatial image carried by the probe pulse. Further applications require the storage of two-dimension image with large information intensity. Image storage could dramatically increase the storage capacity of EIT, and allow for performing multiple quantum in-formation processing. Under the EIT condition, the slowing and storage of image have been obtained in an atomic vapor and a solid, respectively. The diffusion of atomic gas, causing the distortion of the retrieved image, is an unfavorable factor for image storage. Thus, a solid-state medium without atomic diffusion is preferred for practical applications. Recently, due to potential applications in information processing, rare-earth-doped solids have attracted much attention. They offer the spectrum properties of narrow spectrum line and long decoherence time, and can be used to efficiently store light pulse. In this work, we experimentally demonstrate a controllable spatial-frequency routing of image via stored atomic spin coherence in an EIT-driven Pr:YSO(Pr:YSO)crystal. Under the EIT-based light-storage regime, a transverse spatial image carried by the probe pulse is mapped into atomic spin coherence by switching off the write control field, and later retrieved through the opposite operation. By manipulating the frequency and spatial propagation direction of the read control field, the stored image is transformed into a new spatial-frequency channel. Moreover, the image information can be traced simultaneously in its initial and transformed information channels when two read control fields are applied to read out the stored information. Through the above routing, image information can be manipulated coherently and all-optically in a controlled fashion. Such spatial-frequency image routing can be used for routing image information and interfacing communication lines of different information channels, and has important applications in the fields of image processing and information network.