Precise optical measurements have so far been conducted mainly in the visible and near-uv part of the spectrum. Extension to the far uv region depends on the development of tunable coherent sources that provide high resolution, accurate wavelength metrology, and a large photon flux. As part of our ongoing effort to measure the ionization energy of atomic helium by two- photon excitation at 120.28 nm, we have developed improved methods for generating vuv radiation in the vicinity of 120 nm, and for accurately measuring the systematic frequency shifts that occur during amplification and nonlinear mixing of nanosecond laser pulses.
{"title":"Precise pulsed laser spectroscopy in the visible and far uv region: toward the measurement of the 11S-21S interval in atomic helium","authors":"S. Gangopadhyay, N. Melikechi, E. Eyler","doi":"10.1364/hrs.1993.wb8","DOIUrl":"https://doi.org/10.1364/hrs.1993.wb8","url":null,"abstract":"Precise optical measurements have so far been conducted mainly in the visible and near-uv part of the spectrum. Extension to the far uv region depends on the development of tunable coherent sources that provide high resolution, accurate wavelength metrology, and a large photon flux. As part of our ongoing effort to measure the ionization energy of atomic helium by two- photon excitation at 120.28 nm, we have developed improved methods for generating vuv radiation in the vicinity of 120 nm, and for accurately measuring the systematic frequency shifts that occur during amplification and nonlinear mixing of nanosecond laser pulses.","PeriodicalId":109383,"journal":{"name":"High Resolution Spectroscopy","volume":"249 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124744470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We report on the use of a stimulated Raman transition in a slowed atomic beam to produce a narrow velocity distribution of atoms in a selected electronic state, which could be used for atomic collisions studies in the low temperature regime(1). The velocity selection is part of the deceleration process and in this sense it is unique. The atomic beam is decelerated by the radiation pressure force exerted on the atoms by a counter- propagating laser beam. The resonance condition is maintained along the deceleration path because the changing Doppler shift is compensated by Zeeman tuning the electronic sublevels(2) with a spatialy inhomogneous magnetic field. At the end of the slowing process, the initial Maxwell-Boltzman distribution is compressed to a narrow velocity distribution (Δv ~ 50 m/s), centered close to v = 0. This velocity bunching(3) increases considerably the number of atoms in each velocity class, allowing the use of velocity selection techniques as a feasible way of studying low velocity collisions.
{"title":"Ultra-Narrow Velocity Distributions of Slow Atoms Produced with the Zeeman Tuning Technique","authors":"S. Zilio, V. Bagnato","doi":"10.1364/hrs.1993.thb3","DOIUrl":"https://doi.org/10.1364/hrs.1993.thb3","url":null,"abstract":"We report on the use of a stimulated Raman transition in a slowed atomic beam to produce a narrow velocity distribution of atoms in a selected electronic state, which could be used for atomic collisions studies in the low temperature regime(1). The velocity selection is part of the deceleration process and in this sense it is unique. The atomic beam is decelerated by the radiation pressure force exerted on the atoms by a counter- propagating laser beam. The resonance condition is maintained along the deceleration path because the changing Doppler shift is compensated by Zeeman tuning the electronic sublevels(2) with a spatialy inhomogneous magnetic field. At the end of the slowing process, the initial Maxwell-Boltzman distribution is compressed to a narrow velocity distribution (Δv ~ 50 m/s), centered close to v = 0. This velocity bunching(3) increases considerably the number of atoms in each velocity class, allowing the use of velocity selection techniques as a feasible way of studying low velocity collisions.","PeriodicalId":109383,"journal":{"name":"High Resolution Spectroscopy","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115899449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：