A corona excited supersonic expansion (CESE) source (1) has properties that are well suited to the study of transient molecular species with a high resolution Fourier transform spectrometer. This source is run with a continuous dc discharge and a high speed Roots pumping system. The source of transient molecules is relatively confined and quite intense when compared to flowing afterglow or hollow cathode sources. The discharge serves not only to produce the transient molecules, but also to excite the desired molecules into high electronic states, which can be observed by emission in the ultraviolet and visible spectral regions. The supersonic expansion of the source rotationally cools the transients, thereby reducing spectral congestion from overlapping bands and reducing the Doppler line width of the rotational transitions.
{"title":"High Resolution Fourier Transform Emission Spectroscopy of Transient Molecules Using a Corona Excited Supersonic Expansion Source","authors":"P. Carrick, C. Brazier","doi":"10.1364/hrfts.1992.thd8","DOIUrl":"https://doi.org/10.1364/hrfts.1992.thd8","url":null,"abstract":"A corona excited supersonic expansion (CESE) source (1) has properties that are well suited to the study of transient molecular species with a high resolution Fourier transform spectrometer. This source is run with a continuous dc discharge and a high speed Roots pumping system. The source of transient molecules is relatively confined and quite intense when compared to flowing afterglow or hollow cathode sources. The discharge serves not only to produce the transient molecules, but also to excite the desired molecules into high electronic states, which can be observed by emission in the ultraviolet and visible spectral regions. The supersonic expansion of the source rotationally cools the transients, thereby reducing spectral congestion from overlapping bands and reducing the Doppler line width of the rotational transitions.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"19 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":"128257721","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}
This paper will first describe the optoelectronic generation and detection of freely-propagating fsec pulses of THz electromagnetic radiation, and then applications of the THz beam system to THz time-domain spectroscopy (TDS) will be presented. Via optoelectronic excitation, a transient point source of THz radiation is generated at the focus of a dielectric collimating lens, followed by an additional paraboloidal focusing and collimating mirror. This source produces well collimated beams of fsec pulses of THz radiation. Matched to an identical receiver, the resulting system has extremely high collection efficiency (1). With a demonstrated signal-to-noise ratio of 1000, a time resolution of less than 150 fsec and a frequency range from 0.2 THz to more than 5 THz, (1 THz = 33.3 cm-1 = 4.1 meV), the performance of this optoelectronic THz system is limited by the intrinsic response time of the semiconductor (2).
{"title":"Comparison of THz (far-infrared) time domain spectroscopy and FTS methods","authors":"D. Grischkowsky","doi":"10.1364/hrfts.1992.fc1","DOIUrl":"https://doi.org/10.1364/hrfts.1992.fc1","url":null,"abstract":"This paper will first describe the optoelectronic generation and detection of freely-propagating fsec pulses of THz electromagnetic radiation, and then applications of the THz beam system to THz time-domain spectroscopy (TDS) will be presented. Via optoelectronic excitation, a transient point source of THz radiation is generated at the focus of a dielectric collimating lens, followed by an additional paraboloidal focusing and collimating mirror. This source produces well collimated beams of fsec pulses of THz radiation. Matched to an identical receiver, the resulting system has extremely high collection efficiency (1). With a demonstrated signal-to-noise ratio of 1000, a time resolution of less than 150 fsec and a frequency range from 0.2 THz to more than 5 THz, (1 THz = 33.3 cm-1 = 4.1 meV), the performance of this optoelectronic THz system is limited by the intrinsic response time of the semiconductor (2).","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"22 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":"131508095","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}
The Los Alamos Fourier transform spectrometer (FTS) was designed using the same principles as those of the Kitt Peak FTS.1 The Los Alamos FTS has two 8-in. cat's-eye reflectors moving on oil bearings with a travel of 1 meter for each reflector (Fig. 1). The optical path is folded to conserve space through the use of two 8-in. flat mirrors. The beam splitter is composed of two partially reflecting plates mounted one over the other. In this optical arrangement, the upper plate acts as a beam splitter and the bottom plate a beam recombiner. These plates are mounted in a turret that holds two more beam splitters and this turret can be easily rotated to select a different beam splitter. The optical arrangement allows for two light inputs and two light outputs. The two inputs are located at the end of the instrument and at the side. The two outputs are located at the front of the instrument. All important optical elements can be adjusted externally.
{"title":"Design and Characterization of the Los Alamos Fourier Transform Spectrometer","authors":"B. Palmer","doi":"10.1364/hrfts.1989.tub1","DOIUrl":"https://doi.org/10.1364/hrfts.1989.tub1","url":null,"abstract":"The Los Alamos Fourier transform spectrometer (FTS) was designed using the same principles as those of the Kitt Peak FTS.1 The Los Alamos FTS has two 8-in. cat's-eye reflectors moving on oil bearings with a travel of 1 meter for each reflector (Fig. 1). The optical path is folded to conserve space through the use of two 8-in. flat mirrors. The beam splitter is composed of two partially reflecting plates mounted one over the other. In this optical arrangement, the upper plate acts as a beam splitter and the bottom plate a beam recombiner. These plates are mounted in a turret that holds two more beam splitters and this turret can be easily rotated to select a different beam splitter. The optical arrangement allows for two light inputs and two light outputs. The two inputs are located at the end of the instrument and at the side. The two outputs are located at the front of the instrument. All important optical elements can be adjusted externally.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"114 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":"115672450","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}
DC and microwave discharges are often used to excite emission spectra that can be observed by Fourier transform spectroscopy. Here we report the use of two methods which are less often used but which are particularly well suited to FT recording of spectra of free radicals and ions.
{"title":"Fourier Transform Spectroscopy of Free Radicals and Ions","authors":"M. Vervloet","doi":"10.1364/hrfts.1989.wb4","DOIUrl":"https://doi.org/10.1364/hrfts.1989.wb4","url":null,"abstract":"DC and microwave discharges are often used to excite emission spectra that can be observed by Fourier transform spectroscopy. Here we report the use of two methods which are less often used but which are particularly well suited to FT recording of spectra of free radicals and ions.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"143 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":"129016642","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}
Even after years of development, data reduction software remains the weakest link in the chain of events leading from source preparation to published spectroscopic papers. Most of the time is spent there, yet the quality of the published numbers often fails to reflect the quality of the original spectra; the quantity of information is also usually greatly reduced.
{"title":"High Precision Fourier Transform Spectrometry: Some Observations on Data Reduction","authors":"J. Brault","doi":"10.1364/hrfts.1989.tub3","DOIUrl":"https://doi.org/10.1364/hrfts.1989.tub3","url":null,"abstract":"Even after years of development, data reduction software remains the weakest link in the chain of events leading from source preparation to published spectroscopic papers. Most of the time is spent there, yet the quality of the published numbers often fails to reflect the quality of the original spectra; the quantity of information is also usually greatly reduced.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"28 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":"133573574","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 present the design of a portable heterodyned holographic FTS (HHFTS). The instrument is based on a Michelson interferometer and uses a linear detector array to read out the interferogram. A purpose-built, all-reflecting lens is used for fringe imaging and a cylindrical lens is incorporated for light collection in the along-fringe direction
{"title":"Portable FTS for Field Spectroscopy","authors":"K. Dohlen, A. Canas","doi":"10.1364/hrfts.1992.fd7","DOIUrl":"https://doi.org/10.1364/hrfts.1992.fd7","url":null,"abstract":"We present the design of a portable heterodyned holographic FTS (HHFTS). The instrument is based on a Michelson interferometer and uses a linear detector array to read out the interferogram. A purpose-built, all-reflecting lens is used for fringe imaging and a cylindrical lens is incorporated for light collection in the along-fringe direction","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"79 3 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":"134293635","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}
Noise in a FTS is characterized by source and by frequency spectrum and can be reduced through the design and operation.
傅立叶变换中的噪声具有源和频谱的特征，可以通过设计和操作来减小。
{"title":"Noise in a Fourier Transform Spectrometer: Reduction by Design","authors":"B. Palmer","doi":"10.1364/hrfts.1992.saa2","DOIUrl":"https://doi.org/10.1364/hrfts.1992.saa2","url":null,"abstract":"Noise in a FTS is characterized by source and by frequency spectrum and can be reduced through the design and operation.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"21 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":"131169842","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}
The emission spectrum of neutral titanium has been analysed in the region 1750 - 55 000 Å. For the registrations in the infrared and visible wavelength regions, the Fourier transform spectrometer at Kitt Peak National Observatory has been used, while the recordings in the ultraviolet are from the 10.7-m Eagle spectrograph at National Bureau of Standards, Washington, D.C. In addition to this, a study of the absorption spectrum in the region 1900 - 2315 Å has been performed using plates obtained from Harvard College Observatory. A total of 3377 lines have been identified as belonging to the Ti I spectrum, combining 439 energy levels. About 115 new energy levels have been found. Almost 15% of the previously listed level values have been discarded but a majority of these could be replaced with new values.
分析了中性钛在1750 ~ 55000 Å区域的发射光谱。红外和可见光波段的配位使用了基特峰国家天文台的傅立叶变换光谱仪，紫外波段的记录使用了华盛顿特区国家标准局的10.7 m Eagle光谱仪。此外，利用哈佛大学天文台获得的底片对1900 - 2315 Å区域的吸收光谱进行了研究。共有3377条谱线被确定为属于Ti I光谱，结合了439个能级。已经发现了大约115个新的能级。之前列出的关卡值中约有15%已被丢弃，但其中大部分可以被新值所取代。
{"title":"The Spectrum and Term System of Ti I","authors":"P. Forsberg","doi":"10.1364/hrfts.1989.tua4","DOIUrl":"https://doi.org/10.1364/hrfts.1989.tua4","url":null,"abstract":"The emission spectrum of neutral titanium has been analysed in the region 1750 - 55 000 Å. For the registrations in the infrared and visible wavelength regions, the Fourier transform spectrometer at Kitt Peak National Observatory has been used, while the recordings in the ultraviolet are from the 10.7-m Eagle spectrograph at National Bureau of Standards, Washington, D.C. In addition to this, a study of the absorption spectrum in the region 1900 - 2315 Å has been performed using plates obtained from Harvard College Observatory.\u0000 A total of 3377 lines have been identified as belonging to the Ti I spectrum, combining 439 energy levels. About 115 new energy levels have been found. Almost 15% of the previously listed level values have been discarded but a majority of these could be replaced with new values.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"55 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":"131175771","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}
The CN free radical is commonly observed in flames, in the combustion of propellants and in a variety of astronomical sources. The A2Π-X2Σ+ and the B2Σ+-X2Σ+ electronic transitions were observed in a corona-excited supersonic jet expansion source using methyl azide (CH3N3) in helium. The rotationally cold but vibrationally and electronically hot spectra of CN were recorded at high resolution during the course of our work1 on CH3N.
{"title":"Emission Spectroscopy of Transient Molecules","authors":"P. Bernath","doi":"10.1364/hrfts.1992.tha1","DOIUrl":"https://doi.org/10.1364/hrfts.1992.tha1","url":null,"abstract":"The CN free radical is commonly observed in flames, in the combustion of propellants and in a variety of astronomical sources. The A2Π-X2Σ+ and the B2Σ+-X2Σ+ electronic transitions were observed in a corona-excited supersonic jet expansion source using methyl azide (CH3N3) in helium. The rotationally cold but vibrationally and electronically hot spectra of CN were recorded at high resolution during the course of our work1 on CH3N.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"24 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":"125233865","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}
D. Jennings, V. Kunde, P. Ade, R. Barney, G. Bjoraker, J. Bonnal, J. Brasunas, S. Calcutt, R. Carlson, B. Conrath, R. Courtin, R. Dodge, F. M. Flasar, D. Gautier, L. Herath, L. Hom, B. Jacquemin, T. Kingsmill-Vellacott, S. Leete, A. Marten, G. Michel, P. Romani
The Cassini spacecraft, to be sent to Saturn later this decade, will carry an infrared Fourier transform spectrometer. Cassini will orbit Saturn for several years, studying the planet and its largest moon Titan with a variety of remote sensing and in-situ instruments. The infrared spectrometer, CIRS, will investigate the composition and thermal structure of the atmospheres of Saturn and Titan.
{"title":"CIRS: the Composite Infrared Spectrometer for the Cassini Mission","authors":"D. Jennings, V. Kunde, P. Ade, R. Barney, G. Bjoraker, J. Bonnal, J. Brasunas, S. Calcutt, R. Carlson, B. Conrath, R. Courtin, R. Dodge, F. M. Flasar, D. Gautier, L. Herath, L. Hom, B. Jacquemin, T. Kingsmill-Vellacott, S. Leete, A. Marten, G. Michel, P. Romani","doi":"10.1364/hrfts.1992.fb1","DOIUrl":"https://doi.org/10.1364/hrfts.1992.fb1","url":null,"abstract":"The Cassini spacecraft, to be sent to Saturn later this decade, will carry an infrared Fourier transform spectrometer. Cassini will orbit Saturn for several years, studying the planet and its largest moon Titan with a variety of remote sensing and in-situ instruments. The infrared spectrometer, CIRS, will investigate the composition and thermal structure of the atmospheres of Saturn and Titan.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"213 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":"121333761","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}
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