Deceleration Of Optical Pulses Based On Electromagnetically Induced Transparency Of Rydberg Atoms

The quantum coherence effect generated by the interaction between light and matter has always intrigued scientists in the field of atomic and molecular optical physics,among which the Electromagnetically Induced Transparency(EIT)effect plays an important role in the interaction between light and atoms.When the EIT effect occurs,the absorption of light by the medium is greatly weakened,and the dispersion characteristics are greatly enhanced.Therefore,the EIT effect has great application value in the fields of light speed slowing,optical quantum information storage,photon entanglement,all-optical information processing,coherent system enhanced nonlinearity and so on.In recent years,Rydberg atoms have aroused great research interest due to their novel physical properties such as long lifetime,high polarizability,weak binding energy and strong long-range interaction between atoms.In addition to many other important advances,the experimental realization of the Rydberg atomic EIT provides a new platform for quantum optics and nonlinear effects.The Rydberg atom-based EIT effect has important applications in microwave electric field measurement,quantum control and precision measurement,quantum storage,single photon sources,and quantum entanglement.This thesis mainly introduced the electromagnetic induction transparent effect based on Rydberg atom experiments,using strong dispersion characteristics of high transmission EIT effect.We successfully observed the phenomenon of slowing of light pulses,and explored the influences of coupling optical power and the atomic chamber temperature on delay time,and theoretically results are consistent with the experimental data.This thesis is divided into four parts,as follows,The first chapter introduces the main characteristics of Rydberg atom,the application and development background of EIT effect,and the research progress of optical pulse deceleration in detail.The important position of Rydberg-EIT in the field of quantum optics is emphasized.The possibility of optical pulse deceleration based on the EIT effect of Rydberg atom is further explored through the current situation of light speed deceleration.The second chapter mainly introduces the theoretical basis of optical pulse deceleration based on Rydberg atom electromagnetic induced transparency effect.Based on the optical Bloch equation and Maxwell equation,the absorption and dispersion curves of the two-level and three-level system are studied.Secondly,the concept of phase velocity and group velocity in the process of optical deceleration and the key of realizing the deceleration of light speed are introduced.Finally,the theory of propagation characteristics of Gaussian pulsed light in EIT medium is deduced,which is convenient to compare with the experimental results.The third chapter introduces the construction of Rydberg EIT experimental platform and the experimental equipment of photodeceleration effect.The construction of Rydberg EIT experimental platform mainly introduces the laser system and the PDH frequency stabilization technology involved in the experimental process;For the experiment of optical deceleration effect,our experimental requirements are analyzed,and the relevant parameters of important experimental equipment are introduced.The fourth chapter mainly introduces the main experimental process,experimental results,and theoretical analysis and simulation of the experimental results.Firstly,the relationship between the width of the electromagnetic induced transparent window and the transmission peak height and the coupling light power is explored.Secondly,the delay time of optical pulse deceleration was observed by changing the coupling optical power and the atomic chamber temperature under two-photon resonance condition.Finally,the error analysis of the factors that may affect the experimental results is carried out.The innovation of this paper,1.The laser frequency is locked on the cavity to achieve coherent locking of Rydberg two-step excitation light,and the laser linewidth is less than 100 Hz,which reduces the influence of laser phase noise.2.The power stability of the laser is realized by using the SIM960 feedback control system,and the power stability is increased by an order of magnitude.3.Based on the EIT effect in the Rydberg stepped3-ladder-level-system,the influence of adjusting the coupling optical power and the temperature of the atomic chamber on the delay time of the optical pulse deceleration process is studied,which provides theoretical and experimental guidance for further experimental research on microwave electric field measurement using the optical pulse deceleration technique.