玻色-爱因斯坦凝聚体腔光机械系统中慢光效应研究

摘要：随着Harris[1]等人利用电磁诱导透明技术实现了慢光效应，该现象受到了广泛的研究。同时，慢光效应的研究对非线性光学、光通信和量子信息等领域带来巨大而深刻的影响。本文主要研究的是在玻色-爱因斯坦凝聚体与光腔的耦合的腔光机械系统中的慢光效应。我们首先简单介绍了腔光机械系统的基本概念以及实验上实现的几种典型的腔光机械系统，此外还介绍产生慢光效应的几种机制，并指出我们在玻色—爱因斯坦凝聚体腔光机械系统中主要是利用电磁诱导透明现象产生慢光效应。最后我们从腔光机械系统的哈密顿量出发，推导出算符的海森堡运动方程，并利用输入—输出关系进一步求解得到探测场透射谱以及延迟时间的表达式。根据实验参数，我们通过调整泵浦场的强度可以实现对延迟时间的调节，从而实现了慢光效应。55207

毕业论文关键词: 玻色-爱因斯坦凝聚体，腔光机械系统，慢光效应

Abstract：After Harris et al. observed slow light effect in experiments using the technique of electromagnetically induced transparency (EIT), slow light effects has been under extensive exploration. Investigation of slow light effect can have great and profound impact on the fields of nonlinear optics, optical communications, and quantum information. This paper studies the slow light effect in the optomechanical system composed of Bose-Einstein condensate (BEC) coupled with an optical cavity. We first briefly introduce some basic theory of cavity optomechanics and give some typical examples of optomechanical systems realized in experiments. In addition, we introduce several mechanisms that can be used to produce slow light effect and point out that we mainly use EIT in this BEC-cavity optomechanical system to generate slow light effect. Starting from the Hamiltonian of this coupled system, we derive the Heisenberg equation of motion of the operators and obtain the analytical expression of the probe transmission and the group delay according to the input-output relation. Based on the realistic experimental parameters, we can control the group delay time by adjusting the intensity of the pump field, thus realizing slow light effects.

Keywords: Bose-Einstein condensate, Cavity optomechanical system, Slow light effects

1 绪论 4

1.1 腔光机械系统的研究背景 4

1.2实验上实现的几种腔光机械系统 5

1.3 慢光效应 7

1.4 实现慢光效应的三种方法 8

1.4.1 相干布局数振荡 9

1.4.2受激布里渊散射法 9

1.4.3电磁诱导透明法 10

2玻色-爱因斯坦凝聚体腔光机械系统的慢光效应研究 10

2.1 引言 10

2.2理论模型 11

2.3将哈密顿量变换到泵浦场频率的旋转坐标框架下 12

2.4利用海森堡运动方程计算慢光效应 13

2.5 结果与讨论 16

结论 20

参考文献 21

致谢 22

1 绪论

1.1 腔光机械系统的研究背景

典型的腔光机械系统[2-4]如图1.1所示，构成光腔的两个镜子中左边镜子是固定不动的，而右边的镜子可在其平衡位置附近做微小的来回振动，可当作简谐振子处理。当光腔在左侧受到一束强的泵浦激光驱动时，光子在投射或者反射出光腔前将会被来回玻色-爱因斯坦凝聚体腔光机械系统中慢光效应研究:http://www.751com.cn/wuli/lunwen_59491.html