冷分子激光导引的理论研究

Cold molecules offer some new opportunities for molecular spectroscopy and precision measurements, molecular collisions and cold chemistry, and so on. Generation and controlling of cold molecules is one of the frontlines of molecular optics. In this project, we will carry out a systematic theoretical investigation on laser guiding of cold molecules. Cold molecules will be trapped, guided and controlled by the dipole forces coming from some given optical fields. And cold molecules will be filtered from the input thermal samples and compose cold molecular beams by using some bend optical molecule guides. Since optical fields can interact with all kinds of molecules, our all-optical schemes are rather versatile than electrostatic or magnetostatic ones. To achieve the project objectives, we will combine theoretical analysis with numerical simulation, classical modles with quantum ones and analytical solution with numerical calculation to fumble feasible experimental schemes, and then give theory evidence and technical basis. Cold molecular technique and molecular optics can be developed by this project accordingly.

冷分子在分子光谱、精密测量、分子冷碰撞及冷化学等方面有着非常重要的应用，冷分子的产生及操控是分子光学的前沿。本项目围绕中性分子的激光导引及冷分子束的产生开展理论方案的研究和探索。计划借助于光场与分子的相互作用实现分子的囚禁、导引及操控，采用弯曲导引实现连续或准连续冷分子束的产生，特别是利用光场可与所有分子发生相互作用这一优点解决非极性非磁性分子至今仍不可被导引的难题。通过分析了解分子激光导引亟待解决的研究壁垒及技术瓶颈，尝试设计有效导引分子束的新方案。通过理论研究和模拟相结合、经典和量子相结合以及解析和数值相结合的方法摸索出切实可行的实验方案，为中性分子的激光导引提供理论依据及技术参考，推动冷分子技术及分子光学的发展。

本项目提出一个超辐射测量方案，以实现海森堡极限超分辨位移测量，该方案将多个动量编码到包含多个q光子的三能级原子集合，用2N个相干脉冲制备出由两个定时迪克态精准叠加的q激发超辐射态，从而动量空间分布着4qN个分立的光动量。两个迪克态之间的相差由原子集的统一位移诱导，具有 1/4q N精度。另外本项目分别介绍了在水晶和超冷原子中应用该测量方法的实验。