中文摘要：

在室温铯原子蒸气池中，由铯原子基态、激发态和里德堡态构建了阶梯型三能级系统，研究了里德堡原子阶梯型三能级系统的电磁感应透明（EIT）．在实现电磁感应透明的基础上，利用16．9GHz的射频电场耦合相邻的原子里德堡态，实现49S1／2→47D3／2的双光子跃迁，测量了里德堡原子的射频双光子光谱，观察到了电磁感应透明光谱的分裂，进一步研究了电场强度对射频双光子光谱的影响．利用里德堡原子的EIT效应可实现对射频电场幅值和极化的精密测量，具有潜在的应用前景．

英文摘要：

Rydberg atoms, with large principal quantum number, exhibit certain properties, such as long lifetimes and strong interactions with fields and other atoms, which have been extensively investigated recently. One of the properties is the electromagnetically induced transparency （EIT） of Rydberg ladder system, which can be used to measure the radio frequency （RF） field with high sensitivity. In this paper, we investigate the quantum coherent effect of cesium Rydberg atom in a three-level ladder system involving the ground state （6S1/2）, the excited state （6P3/2） and 49S1/2 Rydberg state in room temperature vapor cell. The probe laser （852 nm） drives the transition of 6S1/2（F = 4） → 6P3/2（F＇ = 5）, while the coupling laser （510 nm） couples the Rydberg transition of 6P3/2 （F＇ = 5） → nS1/2. A typical electromagnetically induced transparency spectrum is obtained when the weak probe laser is scanned through the transition of 6S1/2 （F = 4） → 6P3/2 （F＇ = 5） and the coupling laser tuning to Rydberg transition. The two-photon RF spectra are observed when the RF field with a frequency of -16.9 GHz couples the Rydberg transition of 49S1/2→47D3/2, where the EIT signal is split into two EIT peaks due to the interaction between the RF field and Rydberg atoms. The dependences of EIT splitting on the power of RF field are investigated. The results show that the EIT splitting increases with the power of RF field, which can inversely be used to measure the RF field with a higher spatial resolution in the future.