Department of Physics and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu, 30013, Taiwan.
Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan.
Sci Rep. 2017 Aug 29;7(1):9726. doi: 10.1038/s41598-017-09953-0.
Combination of the electromagnetically-induced-transparency (EIT) effect and Rydberg-state atoms has attracted great attention recently due to its potential application in the photon-photon interaction or qubit operation. In this work, we studied the Rydberg-EIT spectra with room-temperature Rb atoms. Spectroscopic data under various experimental parameters all showed that the contrast of EIT transparency as a function of the probe field intensity is initially enhanced, reaches a maximum value and then decays gradually. The contrast of spectral profile at the optimum probe field intensity is enhanced by 2-4 times as compared with that at weakest intensity. Moreover, the signal-to-noise ratio of the spectrum can potentially be improved by 1 to 2 orders of magnitude. We provided a theoretical model to explain this behavior and clarified its underlying mechanism. Our work overcomes the obstacle of weak signal in the Rydberg-EIT spectrum caused by an apparent relaxation rate of the Rydberg polariton and weak coupling transition strength, and provides the useful knowledge for the Rydberg-EIT study.
电磁感应透明（EIT）效应与里德堡原子的组合由于在光子-光子相互作用或量子位操作中的潜在应用而引起了极大的关注。在这项工作中，我们研究了室温铷原子的里德堡-EIT 光谱。在各种实验参数下的光谱数据均表明，作为探测场强度函数的 EIT 透明对比度最初增强，达到最大值，然后逐渐衰减。与最弱强度相比，在最佳探测场强度下的光谱轮廓对比度增强了 2-4 倍。此外，光谱的信噪比有可能提高 1 到 2 个数量级。我们提供了一个理论模型来解释这种行为，并阐明了其潜在的机制。我们的工作克服了由于里德堡极化激元的明显弛豫率和弱耦合跃迁强度而导致的里德堡-EIT 光谱中弱信号的障碍，并为里德堡-EIT 研究提供了有用的知识。
