铷蒸气Λ-型系统中的受激Raman谱与光泵效应

Stimulated Raman spectrum and optical pumping in a Λ-type Rb vapor system

从理论和实验上研究了85Rb原子蒸气D1线系统中的受激Raman现象.在Λ-型能级系统中,抽运光对弱探测光的影响有两部分:受激Raman激发和光泵效应.在一定的抽运光强度和失谐量条件下,受激Raman谱表现为增益谱或损耗谱;以光泵效应导致的吸收谱为背景时,便分别形成了窄线宽透明窗口或线宽差异很大的吸收双线.理论模拟和实验结果基本符合.基于这些研究,从新的角度阐述了在Λ-型系统中的电磁感应透明和Autler-Townes分裂这两个重要现象与受激Raman谱之间的关系.

Theoretical and experimental studies of stimulated Raman spectrum with the D1 line of an 85Rb atomic vapor system are per- formed. In this A-type system, we discover that the influence of the pump on the probe field includes two parts： stimulated Raman excitation and optical pumping. Depending on the pump frequency detuning and field intensity conditions, the Raman spectrum can display either gain or loss. When the optically pumped absorption spectrum is taken as background, either a narrow transparent win- dow or an absorption doublet with widely different linewidths appears. Our theoretical analysis agrees well with our experimental observations. Based on these studies, we present an interpretation from a new viewpoint of the physics of electromagnetically induced transparency （with on-resonance pumping） and Autler-Townes splitting （with far off-resonance pumping） in a A-type level afomic system, giving the relationship between these two important phenomena and the Raman spectrum.