Pub Date : 1994-08-01DOI: 10.1088/0954-8998/6/4/012
R. Thompson, B. Stoicheff, G. Zhang, K. Hakuta
Four-wave mixing in atomic hydrogen with the generation of coherent Lyman- beta radiation at 102.6 nm was investigated experimentally and theoretically in the low density limit. We demonstrate that in this doubly-resonant system, the application of intense laser radiation to strongly couple the 2s and 3p levels causes transparency in the 3p from 1s transition, leading to reduced absorption of the generated Lyman- beta radiation, and to increased conversion efficiency.
{"title":"Nonlinear generation of 103 nm radiation with electromagnetically-induced transparency in atomic hydrogen","authors":"R. Thompson, B. Stoicheff, G. Zhang, K. Hakuta","doi":"10.1088/0954-8998/6/4/012","DOIUrl":"https://doi.org/10.1088/0954-8998/6/4/012","url":null,"abstract":"Four-wave mixing in atomic hydrogen with the generation of coherent Lyman- beta radiation at 102.6 nm was investigated experimentally and theoretically in the low density limit. We demonstrate that in this doubly-resonant system, the application of intense laser radiation to strongly couple the 2s and 3p levels causes transparency in the 3p from 1s transition, leading to reduced absorption of the generated Lyman- beta radiation, and to increased conversion efficiency.","PeriodicalId":130003,"journal":{"name":"Quantum Optics: Journal of The European Optical Society Part B","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115007605","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}
Pub Date : 1994-08-01DOI: 10.1088/0954-8998/6/4/013
R. Chiao
Analytic, limited-bandwidth signals, e.g. Gaussian wavepackets, whose frequencies lie in a transparent spectral window far below the resonance of an amplifying atomic medium, can propagate with phase, group, energy and 'signal' velocities (as defined by Sommerfeld and Brillouin) all exceeding the vacuum speed of light c. This 'superluminal' propagation may occur without significant distortion or gain. The front velocity, however, is not superluminal, and therefore Einstein causality is not violated. Applications will be discussed, including the possibility of using superluminal atomic coherence in condensed matter (e.g. macroscopic mass currents in superfluid helium which arise from vortex motions) for efficient gravitational antennae.
{"title":"Atomic coherence effects which produce superluminal (but causal) propagation of wavepackets","authors":"R. Chiao","doi":"10.1088/0954-8998/6/4/013","DOIUrl":"https://doi.org/10.1088/0954-8998/6/4/013","url":null,"abstract":"Analytic, limited-bandwidth signals, e.g. Gaussian wavepackets, whose frequencies lie in a transparent spectral window far below the resonance of an amplifying atomic medium, can propagate with phase, group, energy and 'signal' velocities (as defined by Sommerfeld and Brillouin) all exceeding the vacuum speed of light c. This 'superluminal' propagation may occur without significant distortion or gain. The front velocity, however, is not superluminal, and therefore Einstein causality is not violated. Applications will be discussed, including the possibility of using superluminal atomic coherence in condensed matter (e.g. macroscopic mass currents in superfluid helium which arise from vortex motions) for efficient gravitational antennae.","PeriodicalId":130003,"journal":{"name":"Quantum Optics: Journal of The European Optical Society Part B","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116221486","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}
Pub Date : 1994-08-01DOI: 10.1088/0954-8998/6/4/001
M. Scully
Aspects of lasing without inversion (LWI) have been the subject of spirited debate. Analytical solutions are here presented which provide a useful tool for resolving many of the conundrums and also provide new insights into the physics of the problem. The presentation is written for the student with some background in laser physics but not LWI. Some of the material is therefore in the nature of a review.
{"title":"Resolving conundrums in lasing without inversion via exact solutions to simple models","authors":"M. Scully","doi":"10.1088/0954-8998/6/4/001","DOIUrl":"https://doi.org/10.1088/0954-8998/6/4/001","url":null,"abstract":"Aspects of lasing without inversion (LWI) have been the subject of spirited debate. Analytical solutions are here presented which provide a useful tool for resolving many of the conundrums and also provide new insights into the physics of the problem. The presentation is written for the student with some background in laser physics but not LWI. Some of the material is therefore in the nature of a review.","PeriodicalId":130003,"journal":{"name":"Quantum Optics: Journal of The European Optical Society Part B","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121465332","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}
Pub Date : 1994-08-01DOI: 10.1088/0954-8998/6/4/015
R. Hammond
In a quantum coherent system, the effect of the dipole-dipole interactions is calculated for nearest neighbours. A mean theory is used in a lattice gas approximation. It is found that the dipole interaction is negligible for low pressure but begins to have noticeable effects on the susceptibility at a number density of about 1016 cm-3.
{"title":"Enhanced interactions in atomic coherence","authors":"R. Hammond","doi":"10.1088/0954-8998/6/4/015","DOIUrl":"https://doi.org/10.1088/0954-8998/6/4/015","url":null,"abstract":"In a quantum coherent system, the effect of the dipole-dipole interactions is calculated for nearest neighbours. A mean theory is used in a lattice gas approximation. It is found that the dipole interaction is negligible for low pressure but begins to have noticeable effects on the susceptibility at a number density of about 1016 cm-3.","PeriodicalId":130003,"journal":{"name":"Quantum Optics: Journal of The European Optical Society Part B","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121761256","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}
Pub Date : 1994-08-01DOI: 10.1088/0954-8998/6/4/007
K. K. Meduri, P. Sellin, G. A. Wilson, T. Mossberg
We show that continuous-wave, two colour excitation of three-level atoms opens new channels of irreversible population transfer between atomic levels. This process, which we describe as dynamically induced irreversibility, leads to unanticipated phenomena including the inversion of atomic transitions whose upper atomic level has no conventional source of irreversible population pumping. We also study the effect of excitation-field bandwidth on the gain exhibited by driven, three-level, V-type atomic systems. Gain, which may or may not be inversionless in the atomic-state basis, is produced through strong monochromatic driving of one atomic transition and weaker pumping of a coupled transition. It is found that monochromatic pumping frequently yields greater optical gain than incoherent (wide bandwidth) pumping. This is particularly true when system gain can be attributed to hidden inversions among the eigenstates (semi-classical dressed states) of the coupled atom+driving field quantum system. Last, we report the observation of continuous-wave lasing in a strongly driven barium cascade system and interpret its properties in terms of the models presented.
{"title":"Coherently driven three-level atoms: unexpected inversions, pump bandwidth effects and observation of continuous lasing","authors":"K. K. Meduri, P. Sellin, G. A. Wilson, T. Mossberg","doi":"10.1088/0954-8998/6/4/007","DOIUrl":"https://doi.org/10.1088/0954-8998/6/4/007","url":null,"abstract":"We show that continuous-wave, two colour excitation of three-level atoms opens new channels of irreversible population transfer between atomic levels. This process, which we describe as dynamically induced irreversibility, leads to unanticipated phenomena including the inversion of atomic transitions whose upper atomic level has no conventional source of irreversible population pumping. We also study the effect of excitation-field bandwidth on the gain exhibited by driven, three-level, V-type atomic systems. Gain, which may or may not be inversionless in the atomic-state basis, is produced through strong monochromatic driving of one atomic transition and weaker pumping of a coupled transition. It is found that monochromatic pumping frequently yields greater optical gain than incoherent (wide bandwidth) pumping. This is particularly true when system gain can be attributed to hidden inversions among the eigenstates (semi-classical dressed states) of the coupled atom+driving field quantum system. Last, we report the observation of continuous-wave lasing in a strongly driven barium cascade system and interpret its properties in terms of the models presented.","PeriodicalId":130003,"journal":{"name":"Quantum Optics: Journal of The European Optical Society Part B","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125034291","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}
Pub Date : 1994-08-01DOI: 10.1088/0954-8998/6/4/003
G. Meyer, U. Rathe, M. Graf, Shi-Yao Zhu, E. Fry, M. Scully, G. Herling, L. Narducci
The connection and similarity between two different models for lasing without inversion are studied, and various dressed state pictures enlighten its physical origin. Recent experiments on coherence effects in sodium are reviewed. The existence of atomic coherence in these experiments is critically examined. It is found that the hyperfine structure and the coupling coefficients within the sodium D1 manifold are of crucial importance.
{"title":"Atomic coherence effects within the sodium D1 manifold. I. Creation of coherence and dressed state analysis","authors":"G. Meyer, U. Rathe, M. Graf, Shi-Yao Zhu, E. Fry, M. Scully, G. Herling, L. Narducci","doi":"10.1088/0954-8998/6/4/003","DOIUrl":"https://doi.org/10.1088/0954-8998/6/4/003","url":null,"abstract":"The connection and similarity between two different models for lasing without inversion are studied, and various dressed state pictures enlighten its physical origin. Recent experiments on coherence effects in sodium are reviewed. The existence of atomic coherence in these experiments is critically examined. It is found that the hyperfine structure and the coupling coefficients within the sodium D1 manifold are of crucial importance.","PeriodicalId":130003,"journal":{"name":"Quantum Optics: Journal of The European Optical Society Part B","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121923878","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}
Pub Date : 1994-08-01DOI: 10.1088/0954-8998/6/4/002
O. Kocharovskaya, P. Mandel
We derive an amplification condition which generalizes the traditional population inversion requirement for the basic schemes of inversionless amplification. We develop a self-consistent quantum approach for the description of such schemes and demonstrate the limitations of the traditional phenomenological approach.
{"title":"Basic models of lasing without inversion: general form of amplification condition and problem of self-consistency","authors":"O. Kocharovskaya, P. Mandel","doi":"10.1088/0954-8998/6/4/002","DOIUrl":"https://doi.org/10.1088/0954-8998/6/4/002","url":null,"abstract":"We derive an amplification condition which generalizes the traditional population inversion requirement for the basic schemes of inversionless amplification. We develop a self-consistent quantum approach for the description of such schemes and demonstrate the limitations of the traditional phenomenological approach.","PeriodicalId":130003,"journal":{"name":"Quantum Optics: Journal of The European Optical Society Part B","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125506515","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}
Pub Date : 1994-08-01DOI: 10.1088/0954-8998/6/4/011
B. Clark, A. Glueck
We report increased stimulated emission on some optically pumped laser transitions coupled to suppressed stimulated emission on other transitions when a weak Stokes laser beam and a strong pump laser beam interact with K2 molecules in the counterintuitive sequence. The Stokes laser photons begin to interact with the K2 molecules 3 to 4 ns before the pump laser photons can interact with the K2 molecules. Both the Stokes and the pump laser pulses last for approximately 5 ns and the suppressed and enhanced stimulated emissions coincide with the pump laser pulse. The stimulated emissions described in this paper propagate parallel to the Stokes and pump laser beams.
{"title":"K2 optically pumped lasers using temporally delayed pulses in the counterintuitive sequence","authors":"B. Clark, A. Glueck","doi":"10.1088/0954-8998/6/4/011","DOIUrl":"https://doi.org/10.1088/0954-8998/6/4/011","url":null,"abstract":"We report increased stimulated emission on some optically pumped laser transitions coupled to suppressed stimulated emission on other transitions when a weak Stokes laser beam and a strong pump laser beam interact with K2 molecules in the counterintuitive sequence. The Stokes laser photons begin to interact with the K2 molecules 3 to 4 ns before the pump laser photons can interact with the K2 molecules. Both the Stokes and the pump laser pulses last for approximately 5 ns and the suppressed and enhanced stimulated emissions coincide with the pump laser pulse. The stimulated emissions described in this paper propagate parallel to the Stokes and pump laser beams.","PeriodicalId":130003,"journal":{"name":"Quantum Optics: Journal of The European Optical Society Part B","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128649903","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}
Pub Date : 1994-08-01DOI: 10.1088/0954-8998/6/4/016
L. Goldner, C. Gerz, R. Spreeuw, S. Rolston, C. Westbrook, W. Phillips, P. Marte, P. Zoller
We demonstrate a new technique for the mechanical manipulation of atoms with light that may be used to deflect or split an atomic beam. This technique depends on the existence of an internal superposition state of the atom that is 'dark' to resonant excitation by a particular light field. An atom in a dark state may adiabatically follow a slowly varying light field in such a way that both the internal state and the atom's momentum are changed. Because the dark state never absorbs or fluoresces, the atomic coherence, necessary for atom interferometry, is preserved. We use laser-cooled Cs atoms to demonstrate the transfer of 8 photon momenta from the slowly varying laser field to the atom.
{"title":"Coherent transfer of photon momentum by adiabatic following in a dark state","authors":"L. Goldner, C. Gerz, R. Spreeuw, S. Rolston, C. Westbrook, W. Phillips, P. Marte, P. Zoller","doi":"10.1088/0954-8998/6/4/016","DOIUrl":"https://doi.org/10.1088/0954-8998/6/4/016","url":null,"abstract":"We demonstrate a new technique for the mechanical manipulation of atoms with light that may be used to deflect or split an atomic beam. This technique depends on the existence of an internal superposition state of the atom that is 'dark' to resonant excitation by a particular light field. An atom in a dark state may adiabatically follow a slowly varying light field in such a way that both the internal state and the atom's momentum are changed. Because the dark state never absorbs or fluoresces, the atomic coherence, necessary for atom interferometry, is preserved. We use laser-cooled Cs atoms to demonstrate the transfer of 8 photon momenta from the slowly varying laser field to the atom.","PeriodicalId":130003,"journal":{"name":"Quantum Optics: Journal of The European Optical Society Part B","volume":"152 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133459526","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}
Pub Date : 1994-08-01DOI: 10.1088/0954-8998/6/4/004
D. Nikonov, U. Rathe, M. Scully, Shi-Yao Zhu, E. Fry, Xingfu Li, G. Padmabandu, M. Fleischhauer
For pt. I see ibid. p. 231, 1994. We consider optical pumping in the multilevel sodium D1 manifold by several coherent light fields. Coherence between atomic states is taken into account by solving the complete density matrix equations. The manifestation of population trapping and the variation of transmitted light intensity are predicted numerically and verified experimentally for the sodium D1 line. The influence of relaxation and Doppler broadening is elucidated. The interaction of a strong and a weak field is shown to create electromagnetically induced transparency.
{"title":"Atomic coherence effects within the sodium D1 manifold. II. Coherent optical pumping","authors":"D. Nikonov, U. Rathe, M. Scully, Shi-Yao Zhu, E. Fry, Xingfu Li, G. Padmabandu, M. Fleischhauer","doi":"10.1088/0954-8998/6/4/004","DOIUrl":"https://doi.org/10.1088/0954-8998/6/4/004","url":null,"abstract":"For pt. I see ibid. p. 231, 1994. We consider optical pumping in the multilevel sodium D1 manifold by several coherent light fields. Coherence between atomic states is taken into account by solving the complete density matrix equations. The manifestation of population trapping and the variation of transmitted light intensity are predicted numerically and verified experimentally for the sodium D1 line. The influence of relaxation and Doppler broadening is elucidated. The interaction of a strong and a weak field is shown to create electromagnetically induced transparency.","PeriodicalId":130003,"journal":{"name":"Quantum Optics: Journal of The European Optical Society Part B","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122529895","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：