基于铷原子双光子跃迁的原子谱线展宽机制教学演示  

TEACHING DEMONSTRATION OF SPECTRUM BROADENING IN TWO-PHOTO TRANSITION OF RB

作　　者：王铿淇 郭进先 WANG Kengqi;GUO Jinxian(School of Physics and Astronomy,Shanghai Jiao Tong University,Shanghai 200240)

机构地区：[1]上海交通大学物理与天文学院,上海200240

出　　处：《物理与工程》2023年第2期119-125,共7页Physics and Engineering

基　　金：上海市科技英才杨帆计划(19YF1421800);国家自然科学基金(11904227)资助

摘　　要：测量原子光谱是揭示微观粒子微观结构与运动规律的重要手段,因而从本科到研究生阶段都会涉及到相关领域的教学,特别是光谱的相关教学。然而,由多普勒效应等引起的非均匀展宽及原子碰撞等引起的均匀展宽极大限制了谱线的分辨精度。在科学技术的发展中,为了获得更高的分辨精度,消除原子谱线的展宽成为重点研究方向。而在相关教学方面,碱金属原子体系由于其优异的能级特性,成为了研究展宽机制的有效途径。而在目前的本科教学中,缺乏除对多普勒展宽以外的多种原子谱线展宽机制的演示。因此,本文利用铷原子5S_(1/2)→5P_(3/2)→5D_(5/2)双光子跃迁谱线,测量改变激光功率、原子池温度等条件下引起的原子谱线半宽变化,验证双光子跃迁的同时,重点演示了原子谱线展宽的机制以及谱线半宽的测量方法。通过本实验,本科生一方面可以掌握原子谱线展宽与双光子跃迁的相关知识,以更深刻地理解了理论知识的内涵,另一方面通过自主搭建实验仪器锻炼了本科生的动手能力,对提升物理专业本科学生的素养尤为重要。本文所展示的实验装置简单,易于搭建,适合课堂演示和实验教学。The measurement of atomic spectrum is an important tool to reveal the microscopic structure and pattern of motion of microscopic particles.Therefore,the teaching of related fields is involved from undergraduate to graduate stage,especially the teaching of spectroscopy.However,nonuniform broadening caused by Doppler effect and uniform broadening caused by atomic collision greatly limit the resolution of the spectral lines.In the development of science and technology,in order to obtain higher resolution,it is necessary to eliminate the broadening of atomic spectral lines.In the related teaching,two-photon transition in the alkali metal atomic system has become an effective way to study the broadening mechanism due to its excellent energy level characteristics.In the current undergraduate teaching,there is a lack of demonstrations of various atomic line broadening mechanisms besides Doppler broadening.In this paper,the rubidium atom 5S1/2→5P3/2→5D5/2 two-photon transition spectral line is em-ployed to measure the half-width change caused by changing the laser power,the temperature of the atomic cell and magnetic field strength.While verifying the two-photon transition,it focuses on demonstrating the mechanism of the atomic spectral line broadening and the meas-urement method of the half-width of the spectral line.Through this experiment,on the one hand,undergraduate students can grasp the relevant knowledge of atomic spectral line broade-ning and two-photon transition and understand the connotation of theoretical knowledge more deeply,and on the other hand,they have trained their hands-on ability by building experimen-tal instruments independently,which is particularly important for improving the quality of un-dergraduate students majoring in physics.The experimental device shown in this paper is sim-ple,easy to build,and suitable for classroom demonstration and experimental teaching.

关 键 词：原子谱线展宽 双光子跃迁 铷原子 多普勒效应 压力展宽 功率展宽 

分 类 号：G642[文化科学—高等教育学] O433.1-4[文化科学—教育学]