We propose a ``channelization'' architecture to achieve wide-band electromagnetically induced transparency (EIT) and ultra-slow light propagation in atomic Rb-87 vapors. EIT and slow light are achieved by shining a strong, resonant ``pump'' laser on the atomic medium, which allows slow and unattenuated propagation of a weaker ``signal'' beam, but only when a two-photon resonance condition is satisfied. Our wideband architecture is accomplished by dispersing a wideband signal spatially, transverse to the propagation direction, prior to entering the atomic cell. When particular Zeeman sub-levels are used in the EIT system, then one can introduce a magnetic field with a linear gradient such that the two-photon resonance condition is satisfied for each individual frequency component. Because slow light is a group velocity effect, utilizing differential phase shifts across the spectrum of a light pulse, one must then introduce a slight mismatch from perfect resonance to induce a delay. We present a model which accounts for diffusion of the atoms in the varying magnetic field as well as interaction with levels outside the ideal three-level system on which EIT is based. We find the maximum delay-bandwidth product decreases with bandwidth, and that delay-bandwidth product ~1 should be achievable with bandwidth ~50 MHz (~5 ns delay). This is a large improvement over the ~1 MHz bandwidths in conventional slow light systems and could be of use in signal processing applications.
Magnetically Induced Transparency-Absorption and Normal-Anomalous Dispersion Characteristics of ${}^{87}\text{Rb}$ Medium or Any J-Type Configuration Atomic Vapors Subject to a Vector Magnetic Field and a Weak Resonant Pump
Alikhanyan National Laboratory (Yerevan Physics Institute)（阿利哈尼扬国家实验室（耶烈万物理研究所））；Institute for Physical Research, Armenian National Academy of Sciences（亚美尼亚国家科学院物理研究所）
Multimode electromagnetically-induced transparency on a single atomic line
实验研究了在复杂时间形状的控制场作用下，铷原子蒸气中5S_1/2-5P_1/2非均匀加宽跃迁产生的电磁感应透明（EIT）。梳状透明光谱增强了延迟带宽产品和光存储容量为一个匹配的探测脉冲的一个因素约50相比，一个单一的EIT线[D. D. Yavuz，Phys.Rev.A75，031801（2007）]。如果控制场的时间模式在探针传播通过EIT介质时缓慢改变，则探针将自动跟随，从而提供执行频率转换和光学路由的手段。
光纤中的光存储是量子光延迟线技术中的一个有吸引力的部件。尽管硅芯光纤在传输宽带光信号方面表现出色，但调整其色散特性以减慢光脉冲或将其存储在硅芯中长延迟时间是具有挑战性的。利用色散相干介质与光纤耦合可以实现长光延迟。在这里，我们加载冷Rb原子蒸气到空芯光子晶体光纤内的光阱，并存储在由原子形成的长寿命自旋波的光的相位，并使用电磁诱导透明（EIT）在完全可控的延迟时间后恢复它。我们实现了超过50 ms的存储时间，结果相当于光纤中8.7x10^-5 dB s^-1的传播损耗。我们的演示可用于缓冲和调节远程网络之间的经典和量子信息流。
