We present loss-energy spectra, Im ε -1Ω ), calculated by use Kramers- Kronig transformation to the far-infrared reflectivity spectra of the superconducting YBa2Cu3O7-x, Bi4Sr4CaCu3O14+x, Bi2Sr2CaCu2O8+x a-axis oriented textures in a frequency range 50 - 700 cm-1 at temperatures 20 - 300 K, focusing on the phonon properties in the undoped structures. Fano-like antiresonance minima near 300 cm-1 has been observed in a-axis oriented textures well below Tc and analyzed by Fano configuration interaction theory as result of interference between the B2u (B1g) plane- oxygen mode and low-energy charge continua that arises from electronic excitations on the Fermi surface.
{"title":"Fano electron-phonon effects in the far-infrared properties of high-Tc superconductors","authors":"E. Kafadaryan","doi":"10.1117/12.375284","DOIUrl":"https://doi.org/10.1117/12.375284","url":null,"abstract":"We present loss-energy spectra, Im ε -1Ω ), calculated by use Kramers- Kronig transformation to the far-infrared reflectivity spectra of the superconducting YBa2Cu3O7-x, Bi4Sr4CaCu3O14+x, Bi2Sr2CaCu2O8+x a-axis oriented textures in a frequency range 50 - 700 cm-1 at temperatures 20 - 300 K, focusing on the phonon properties in the undoped structures. Fano-like antiresonance minima near 300 cm-1 has been observed in a-axis oriented textures well below Tc and analyzed by Fano configuration interaction theory as result of interference between the B2u (B1g) plane- oxygen mode and low-energy charge continua that arises from electronic excitations on the Fermi surface.","PeriodicalId":427427,"journal":{"name":"Atomic and Molecular Spectroscopy","volume":"150 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115167782","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}
Quantitative analysis of instabilities in microwave low- temperature plasma is carried out by taking into account electron-electron interactions. In particular, it was obtained that S-type negative differential conductivity (NDC) of electrons can be observed in microwave plasma, if this plasma in dc field displays N-type NDC of electrons (both effects have to be compared at the same value of mean electron energy). The conditions for observation of negative radiation temperature are estimated. Radiation temperature in gas mixture is presented as simple function of plasma macroscopic parameters in single gases composing a given mixture.
{"title":"Analytical prediction of some instabilities in microwave low-temperature plasma","authors":"R. V. Chiflikyan","doi":"10.1117/12.375292","DOIUrl":"https://doi.org/10.1117/12.375292","url":null,"abstract":"Quantitative analysis of instabilities in microwave low- temperature plasma is carried out by taking into account electron-electron interactions. In particular, it was obtained that S-type negative differential conductivity (NDC) of electrons can be observed in microwave plasma, if this plasma in dc field displays N-type NDC of electrons (both effects have to be compared at the same value of mean electron energy). The conditions for observation of negative radiation temperature are estimated. Radiation temperature in gas mixture is presented as simple function of plasma macroscopic parameters in single gases composing a given mixture.","PeriodicalId":427427,"journal":{"name":"Atomic and Molecular Spectroscopy","volume":"149 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124111390","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 adiabatic following condition for the propagation of pulses in a three-level medium has been obtained. It is shown that the adiabatic criterion depends not only on the total Rabi frequency and pulse duration, but on the relationship between oscillator strengths of electric dipole transitions in an atom too. In particular, for (Lambda) - system if the oscillator strength for the pump transition is less or equal to that for the Stokes transition, the adiabatic following condition is preserved at arbitrary penetration depths. Otherwise it breaks down rather quickly with the distance of propagation.
{"title":"Adiabatic following condition for pulse propagation in three-level medium","authors":"G. Grigoryan, Y. Pashayan","doi":"10.1117/12.375298","DOIUrl":"https://doi.org/10.1117/12.375298","url":null,"abstract":"The adiabatic following condition for the propagation of pulses in a three-level medium has been obtained. It is shown that the adiabatic criterion depends not only on the total Rabi frequency and pulse duration, but on the relationship between oscillator strengths of electric dipole transitions in an atom too. In particular, for (Lambda) - system if the oscillator strength for the pump transition is less or equal to that for the Stokes transition, the adiabatic following condition is preserved at arbitrary penetration depths. Otherwise it breaks down rather quickly with the distance of propagation.","PeriodicalId":427427,"journal":{"name":"Atomic and Molecular Spectroscopy","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126819233","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}
An optical system of three-cannal telescope-spectrometer is proposed for the registration of the spectra of individual stars in the extreme short wavelength region, shorter 500 A up to 100 A (project VESTAL). The calculated optical parameters of both components of main telescope, two parabolic mirrors with entrance diameter of 1200 mm and three spectrometers of Wadsworth system, are presented as well.
{"title":"Vestal: space astronomical observatory for the far ultraviolet: 100 to 500 A","authors":"G. A. Gurzadyan, R. Khachatryan","doi":"10.1117/12.375290","DOIUrl":"https://doi.org/10.1117/12.375290","url":null,"abstract":"An optical system of three-cannal telescope-spectrometer is proposed for the registration of the spectra of individual stars in the extreme short wavelength region, shorter 500 A up to 100 A (project VESTAL). The calculated optical parameters of both components of main telescope, two parabolic mirrors with entrance diameter of 1200 mm and three spectrometers of Wadsworth system, are presented as well.","PeriodicalId":427427,"journal":{"name":"Atomic and Molecular Spectroscopy","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134163932","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 problem of a two-level atom interacting with a nonmonochromatic radiation pulse is studied both with and without the resonant approximation. Using the time-dependent perturbation theory, the analytical expressions for transition probability of the atom are obtained. It is shown how, depending on the value of the field strength, the atom's excitation probability can be obtained with the needed accuracy. It is shown that the upper level population of the atom exhibits oscillations which are absent in the resonant approximation. It is shown that absorption probability and dipole moment spectrum are governed by interference between the spectral components of a non- monochromatic radiation involved in nonlinear interaction process. Spectral distribution symmetry with respect to the resonance frequency being destroyed, the atom can be excited even if there is no resonant component in the pulse spectrum.
{"title":"Behavior of two-level atom driven by pulsed radiation","authors":"V. Chaltykyan, G. Grigorian, Y. Pashayan","doi":"10.1117/12.375277","DOIUrl":"https://doi.org/10.1117/12.375277","url":null,"abstract":"The problem of a two-level atom interacting with a nonmonochromatic radiation pulse is studied both with and without the resonant approximation. Using the time-dependent perturbation theory, the analytical expressions for transition probability of the atom are obtained. It is shown how, depending on the value of the field strength, the atom's excitation probability can be obtained with the needed accuracy. It is shown that the upper level population of the atom exhibits oscillations which are absent in the resonant approximation. It is shown that absorption probability and dipole moment spectrum are governed by interference between the spectral components of a non- monochromatic radiation involved in nonlinear interaction process. Spectral distribution symmetry with respect to the resonance frequency being destroyed, the atom can be excited even if there is no resonant component in the pulse spectrum.","PeriodicalId":427427,"journal":{"name":"Atomic and Molecular Spectroscopy","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131058311","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}
In our paper we consider the behavior of both the Hermitian (observable) Stokes parameters of light and the phases difference that describes the polarization state of optical field. In general case we introduce two pairs of phase operators associated with the phase angles in 3D picture for the polarization Stokes parameters of light on the Poincare sphere. The special eight-port polarization interferometer is presented for simultaneous homodyne detection of both the Stokes parameters of light and the polarization phases and also of their fluctuations. It is shown that an anisotropic (spatio-periodically) Kerr-like nonlinear medium placed in the polarization interferometer can be used for generation and observation of the polarization-squeezed phase states of light.
{"title":"Quantum polarimeter for measurement of nonclassical polarization states of light","authors":"A. Alodjants, A. Y. Leksin, S. Arakelian","doi":"10.1117/12.375304","DOIUrl":"https://doi.org/10.1117/12.375304","url":null,"abstract":"In our paper we consider the behavior of both the Hermitian (observable) Stokes parameters of light and the phases difference that describes the polarization state of optical field. In general case we introduce two pairs of phase operators associated with the phase angles in 3D picture for the polarization Stokes parameters of light on the Poincare sphere. The special eight-port polarization interferometer is presented for simultaneous homodyne detection of both the Stokes parameters of light and the polarization phases and also of their fluctuations. It is shown that an anisotropic (spatio-periodically) Kerr-like nonlinear medium placed in the polarization interferometer can be used for generation and observation of the polarization-squeezed phase states of light.","PeriodicalId":427427,"journal":{"name":"Atomic and Molecular Spectroscopy","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128270489","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 observation of far field spatial distortions of a Bessel beam after passing through a Kerr liquid. A coaxial ring structure has been observed to occur at some threshold power. It consists of two closely spaced (1.5 - 3.5 mrad) sharp rings of comparable intensity and a diffuse inner ring of smaller intensity separated by 8 - 9 mrad. Evolution of the far field pattern with moving the sample along the propagation path of the Bessel beam shows strong dependence of beam distortions upon the position of the sample. The phenomenon is supposed to be due to nonlinearly induced phase aberrations resulting in the distortion of angular spectrum.
{"title":"Spatial distortions of a Bessel beam in a Kerr-type medium","authors":"Suren Sogomonian, R. Barillé, G. Rivoire","doi":"10.1117/12.375305","DOIUrl":"https://doi.org/10.1117/12.375305","url":null,"abstract":"We report on the observation of far field spatial distortions of a Bessel beam after passing through a Kerr liquid. A coaxial ring structure has been observed to occur at some threshold power. It consists of two closely spaced (1.5 - 3.5 mrad) sharp rings of comparable intensity and a diffuse inner ring of smaller intensity separated by 8 - 9 mrad. Evolution of the far field pattern with moving the sample along the propagation path of the Bessel beam shows strong dependence of beam distortions upon the position of the sample. The phenomenon is supposed to be due to nonlinearly induced phase aberrations resulting in the distortion of angular spectrum.","PeriodicalId":427427,"journal":{"name":"Atomic and Molecular Spectroscopy","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134259504","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}
A. Babadjanyan, S. V. Haroutyunyan, K. Nerkararyan
The geometric peculiarities of the rough surface of a metal are revealed, when due to the essential shortening of the wavelength of the surface polariton excited by the light localization in a very small region of a space take place.
在很小的空间区域内，由于光局域化所激发的表面极化子的波长明显缩短，揭示了金属粗糙表面的几何特性。
{"title":"Nature of the enhancement of the nonlinear optical response from rough surface of a metal","authors":"A. Babadjanyan, S. V. Haroutyunyan, K. Nerkararyan","doi":"10.1117/12.375285","DOIUrl":"https://doi.org/10.1117/12.375285","url":null,"abstract":"The geometric peculiarities of the rough surface of a metal are revealed, when due to the essential shortening of the wavelength of the surface polariton excited by the light localization in a very small region of a space take place.","PeriodicalId":427427,"journal":{"name":"Atomic and Molecular Spectroscopy","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123874992","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 role of the initial state preparation of the coherent diffraction of atoms in the field of a standing wave is considered. It is shown that the time evolution of the atomic wave packet with a Gaussian initial momentum distribution of amplitudes, due to the constructive quantum- mechanical interference, occurs practically without transformation of the initial Gaussian form. Depending on the phases of the initial momentum distribution components, the increment of the atomic momentum can vary from the maximum possible amount (determined by the limiting speed of stimulated photon re-emission acts) to zero. Consequently, for Gaussian atoms the standing wave presents an effective mirror with controllable reflection angle.
{"title":"Diffraction of atoms by a standing wave at Gaussian initial momentum distribution of amplitudes","authors":"A. Ishkhanyan","doi":"10.1117/12.375301","DOIUrl":"https://doi.org/10.1117/12.375301","url":null,"abstract":"The role of the initial state preparation of the coherent diffraction of atoms in the field of a standing wave is considered. It is shown that the time evolution of the atomic wave packet with a Gaussian initial momentum distribution of amplitudes, due to the constructive quantum- mechanical interference, occurs practically without transformation of the initial Gaussian form. Depending on the phases of the initial momentum distribution components, the increment of the atomic momentum can vary from the maximum possible amount (determined by the limiting speed of stimulated photon re-emission acts) to zero. Consequently, for Gaussian atoms the standing wave presents an effective mirror with controllable reflection angle.","PeriodicalId":427427,"journal":{"name":"Atomic and Molecular Spectroscopy","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122351517","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 : 1992-05-01DOI: 10.1007/978-3-031-04776-3
S. Svanberg
{"title":"Atomic and Molecular Spectroscopy: Basic Aspects and Practical Applications","authors":"S. Svanberg","doi":"10.1007/978-3-031-04776-3","DOIUrl":"https://doi.org/10.1007/978-3-031-04776-3","url":null,"abstract":"","PeriodicalId":427427,"journal":{"name":"Atomic and Molecular Spectroscopy","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123765572","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：