{"title":"Frequency measurement of FIR laser lines of metrological and astrophysical interest","authors":"N. Ioli, A. Moretti, D. Pereira, F. Strumia","doi":"10.1109/irmm.1987.9126913","DOIUrl":null,"url":null,"abstract":"The optically pumped FIR lasers are the most convenient sources of CW radiation in the 1 THz to 6 THz region. The frequency stability and reproducibility (a few parts in 10<sup>7</sup>) makes the FIR lasers a source suitable as a local oscillator for high sensitivity heterodyne spectrometers of astrophysical interest, and as a stable oscillator for Stark and Zeeman intracavity spectroscopy. Moreover the fine structure atomic transitions in the far infrared have a considerable practical interest. As an example, the fine structure transitions between the metastable triplet levels <sup>3</sup>P<inf>2</inf>, <sup>3</sup>P<inf>1</inf>, <sup>3</sup>P<inf>0</inf> of Magnesium and Calcium, at 0.6, 1.2, 1.5, and 3.1 THz respectively, are of relevant metrological interest, because they can be used as a reference for a new kind of absolute atomic frequency standards [1,2]; while the N<sup>+3</sup>P<inf>2</inf> – <sup>3</sup>P<inf>1</inf> transition, which has recently been measured in the laboratory by Cooksy et al. [3], is of particular interest from an astronomical point of view. The discovery of this transition in the interstellar medium seems to be possible, at least in principle.","PeriodicalId":399243,"journal":{"name":"1987 Twelth International Conference on Infrared and Millimeter Waves","volume":"17 6","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"1987-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"1987 Twelth International Conference on Infrared and Millimeter Waves","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/irmm.1987.9126913","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 1
Abstract
The optically pumped FIR lasers are the most convenient sources of CW radiation in the 1 THz to 6 THz region. The frequency stability and reproducibility (a few parts in 107) makes the FIR lasers a source suitable as a local oscillator for high sensitivity heterodyne spectrometers of astrophysical interest, and as a stable oscillator for Stark and Zeeman intracavity spectroscopy. Moreover the fine structure atomic transitions in the far infrared have a considerable practical interest. As an example, the fine structure transitions between the metastable triplet levels 3P2, 3P1, 3P0 of Magnesium and Calcium, at 0.6, 1.2, 1.5, and 3.1 THz respectively, are of relevant metrological interest, because they can be used as a reference for a new kind of absolute atomic frequency standards [1,2]; while the N+3P2 – 3P1 transition, which has recently been measured in the laboratory by Cooksy et al. [3], is of particular interest from an astronomical point of view. The discovery of this transition in the interstellar medium seems to be possible, at least in principle.