基于相干原子气体的强色散特性实现干涉仪的光谱高精度测量

High precision measurement of optical spectrum is the basis of optical measurement. Enhancing precision of optical spectrum measurement by the use of quantum effects has attracted considerable attention recent years. High precision measurement of optical spectrum with interferometer can be realized by fast and slow light properties of dispersive systems. Among various dispersive systems, coherent atomic vapors, based on quantum control, possess many advantages such as strong dispersion, optical frequency response, adjustability by external fields and isotropy. In addition, when coherent atomic vapors are coupled with external fields, negative permittivity, negative permeability, or even negative refraction can be realized. Furthermore, compound systems like multilayer structures can be constructed with atomic vapors, in which the dispersion and loss of light can be well controlled. So, coherent atomic vapors are promising media to realize high precision measurement of optical spectrum with interferometer. We will theoretically study possible ways and solutions to realize high precision measurement of optical spectrum with interferometer when strong dispersive atomic vapors and their compound systems are placed in interferometer. The main contents of this project include: (1) Realizing highly dispersive, broadband, highly controllable coherent atomic vapors; (2) Studying dielectric properties of multilayer structures containing coherent atomic vapors; (3) Realizing high precision measurement of optical spectrum with interferometer by the strong dispersive properties of coherent atomic vapors, combining slow-light atomic vapors with fast-light atomic vapors and the multilayer structures with atomic vapors. According to the research of this project, we will provide theoretical basis for the high precision measurement of optical spectrum.

光谱的高精度测量是光学测量的基础，近年来，利用量子效应提高光谱测量精度受到高度关注。利用色散体系的快慢光性质可以实现干涉仪的光谱高精度测量。在众多色散体系中，量子调控的相干原子气体具有强色散、光频段响应、外场可调、各向同性等优点，还表现出负介电常数、负磁导率、负折射率等特异的电磁性质，且可以构成多层结构的复合体系以调控介质中光场的色散和损耗，因此是实现干涉仪的光谱高精度测量的一种很有前景的介质。本项目拟在干涉仪中加入强色散原子气体或含原子气体的多层结构体系，理论上研究实现干涉仪的光谱高精度测量的可能途径和方案。主要研究内容包括：（1）强色散、宽频带、高可控性相干原子气体的实现；（2）含相干原子气体的多层结构体系的介电性质；（3）利用相干原子气体、快慢光原子气体相结合及含相干原子气体的多层结构的强色散特性实现干涉仪的光谱高精度测量。本项目的研究将为实现光谱的高精度测量提供重要的理论基础。

光谱的高精度测量是光学测量的基础，利用量子效应提高光谱测量精度近年来受到高度关注。利用色散体系的快慢光性质可以实现干涉仪的光谱高精度测量。在众多色散体系中，量子调控的相干原子气体具有强色散、光频段响应、外场可调、各向同性等优点，还表现出负介电常数、负磁导率、负折射率等特异的电磁性质，且可以构成多层结构的复合体系以调控介质中光场的色散和损耗，因此是实现干涉仪的光谱高精度测量的一种很有前景的介质。本项目首先研究了利用单光子散射过程制备两辐射子纠缠态，研究表明：处于对称叠加态的光子被两个辐射子散射时，会在其中一个辐射子处发生频率转换，同时这个辐射子由初始低能态跃迁至其另一个低能态。在该散射过程中，两个辐射子对于入射光子来说是不可区分的。我们无法确定哪一个辐射子发生了跃迁，所以两个辐射子就被制备到了纠缠态。一般三能级原子的两个低能态是长寿命态，耗散很慢，所以我们制备出的纠缠态是长寿命态。其次，基于辐射子-波导的手性耦合系统，我们提出了一种具有很高光谱分辨率，并具有微纳尺寸的法布里-珀罗干涉仪，研究表明：单个辐射子对于波导光子表现出了强色散性质，而整个系统具有与慢光干涉仪一样的功能，对波导光子具有很高的光谱分辨率。我们发现在辐射子共振频率附近，该干涉仪具有很窄的透射条纹。在实际参数下，干涉仪条纹的半高全宽比相同尺度的真空腔减少了至少 5 个量级。