Slowing, Cooling, and Laser Spectroscopy of Helium Atoms and CaF Molecules

本研究项目主要研究高偶极单氟化钙分子的激光减速、冷却和光谱学。选择CaF部分是出于它的基本兴趣，部分是因为它的轻质量和简单的能级结构使它们成为光力操纵的优秀候选者。主要有两个目标：(1)利用光学双色力实现激光减速和冷却的新方法。这是来自双色光束的强大光力，可以使原子或分子在几厘米内停止。将双色力方法扩展到分子中为重大进展提供了机会，因为即使对于缺乏完全封闭的两级循环转变的物种，它也能够进行大的动量交换。(2) CaF分子光谱学。实验将探索高激发态的致密冷气体的物理和相互作用，在这种状态下，一个激发态的电子围绕一个处于基态的离子核运行。特别感兴趣的是高偶极CaF分子的冷分子里德伯气体的物理和化学，包括低温分子-分子碰撞的影响。这项研究将对基础原子和分子物理学做出最大的贡献，但也可能导致光学双色力在分子光谱和化学中的新应用，并将对基于微控制器的激光仪器做出贡献。

This research project focuses on the laser deceleration, cooling and spectroscopy of the highly dipolar calcium monofluoride molecule, CaF. The choice CaF is motivated partially by its fundamental interest, and partially because its light mass and simple energy level structure make them excellent candidates for optical force manipulation. There are two principal objectives:(1) New methods for laser slowing and cooling using optical bichromatic forces. These are strong optical forces from two-color beams that can bring atoms or molecules to a stop in just a few centimeters. The extension of bichromatic force methods to molecules offers opportunities for major advances, because it is capable of large momentum exchanges even for species lacking a fully closed two-level cycling transition.(2) Spectroscopy of CaF molecules. Experiments will probe the physics and interactions of dense cold gases of highly excited "Rydberg" states, in which an excited electron orbits an ionic core in its ground state. Of particular interest is the physics and chemistry of cold molecular Rydberg gases of highly dipolar CaF molecules, including the effects of low-temperature molecule-molecule collisions.This research will contribute most strongly to basic atomic and molecular physics, but will also likely lead to new applications of optical bichromatic forces to molecular spectroscopy and chemistry, and will make contributions to microcontroller-based laser instrumentation.