E. Alipieva - Academia.edu (original) (raw)
Papers by E. Alipieva
Optics and Spectroscopy, Sep 1, 1997
Journal of Physics: Conference Series, 2021
We review three laser spectroscopy schemes developed recently for observation of high-contrast en... more We review three laser spectroscopy schemes developed recently for observation of high-contrast enhanced-absorption nonlinear resonances in small alkali-vapor cells. In our experiments, optical transitions within the cesium D1 line are involved and a probe beam transmission is analyzed. The first spectroscopy method is based on the configuration with two-frequency counter propagating beams, which are linearly polarized in orthogonal directions. This configuration provides observation of high-contrast natural-linewidth resonances superimposed on broad Doppler profiles when the laser frequency is scanned. These resonances have good prospects for developing a miniature optical frequency reference. The second scheme involves two-frequency counter propagating beams with equal circular polarizations and provides observation of subnatural-linewidth resonances when the Raman frequency detuning is scanned. We use these resonances for stabilizing the microwave frequency of a local oscillator (...
Journal of Physics: Conference Series, 2020
We present an experimental investigation of electromagnetically-induced absorption (EIA) at the D... more We present an experimental investigation of electromagnetically-induced absorption (EIA) at the D1 line of 87Rb contained in an anti-relaxation coated vacuum optical cell. The configuration includes a pump and a probe beam propagating in opposite directions and having mutually orthogonal linear polarizations; the probe beam absorption is registered depending on the value of a magnetic field scanned around zero and applied collinearly to the laser beams. The advantages of this scheme have been recently evidenced in vapor cells filled with a buffer gas. In the present work we studied the width and the contrast of the EIA resonances obtained in a coated cell for different values of the pump power. The results are compared with those obtained in a buffer gas cell for the same transition of 87Rb. The theoretical calculations are in good agreement with the experiment.
Optics and Spectroscopy, 2019
The nonlinear Hanle effect is generally considered in the modern literature as a particular case ... more The nonlinear Hanle effect is generally considered in the modern literature as a particular case of coherent population trapping (CPT) at degenerate Zeeman sublevels of the ground atomic state. The shape, amplitude, and sign of observed resonances and their dependence on the excitation parameters and observation geometry were investigated theoretically and experimentally in many studies because of the wide range of application of this effect. The sensitivity of Hanle resonances to the experimental conditions increases significantly in cells with antirelaxation coating, because the atomic ensemble retains its coherence after a large number of collisions with the cell walls. In this paper, the main attention is paid to the joint influence of the excitation radiation intensity and spurious magnetic fields on CPT resonances observed in fluorescence. The theoretical description is based on the numerical solution of an algebraic system of equations for density matrix in the formalism of irreducible tensor operators. The parameters relating different polarization moments in each equation are visualized using the modified sparse matrix of the system. It is established by numerical simulation that the shape, width, amplitude, and sign of nonlinear magnetooptical resonances change nonmonotonically with a change in the parameters of the excitation radiation and atomic system. The presented theoretical results are in good agreement with the experimental data obtained under various conditions.
SPIE Proceedings, 2016
COSMA-Coherent Optics Sensors for Medical Application is an European Marie Curie Project running ... more COSMA-Coherent Optics Sensors for Medical Application is an European Marie Curie Project running from 2012 to March 2016, with the participation of 10 teams from Armenia,
The ultra narrow resonances, obtained by means of polarization spectroscopy of alkali atoms, orig... more The ultra narrow resonances, obtained by means of polarization spectroscopy of alkali atoms, originate from the destruction of the laser-induced coherence in the ground state. In the case of single-frequency, near resonance excitation and suitable geometry the well-known ground state Hanle effect is observed. Coherent population trapping in Hanle configuration is a nonlinear modification of this effect, observed in the fluorescence from the upper level. The ground state coherence is transmitted from the laser field and higher rank polarization moments are created. Using the irreducible tensor operator formalism programs for numerical modelling of this effect has been developed and presented here. The velocity distribution of the atoms, the Gaussian distribution of the laser beam, stray magnetic field, and the experimental geometry are taken into account. The scheme of conversion of the octupole (κ = 3) and hexadecapole (κ = 4) polarization moments (PM) through the laser and magnetic fields into the upper level quadropoles f 2 q is proposed. The conversion of the high-rank polarization moments (PM) into observable components is also discussed. The results of the modelling are compared with the measured ones at different experimental conditions.
A theoretical description is given of interference effects in the spontaneous emission from a cas... more A theoretical description is given of interference effects in the spontaneous emission from a cascade laser, i.e., a laser operating on successively coupled transitions. The kinetic equation of a cascade laser in a magnetic field is considered, and a description is given of depolarization signals and the related anisotropy of spontaneous emission. General expressions are obtained which can be used
Journal of the Optical Society of America A, 1990
An experimental investigation of spectral dependence of two recently discovered anomalies in deep... more An experimental investigation of spectral dependence of two recently discovered anomalies in deep metallic gratings is presented. Good coincidence with theoretical results is obtained. It is shown that the Brewster effect in deep gratings is suppressed with a decrease of wavelength, as the angle of incidence approaches zero. At the same time the groove-depth interval widens, and low values of reflectivity are observed.
Journal of Physics B: Atomic and Molecular Physics, 1985
This paper presents a theoretical investigation of some peculiarities of alignment signals from l... more This paper presents a theoretical investigation of some peculiarities of alignment signals from laser levels carried out in simultaneous oscillation of two transitions connected by spontaneous emission. An expression is obtained for a spontaneous emission part caused by the oscillation originating from the lower laser level. It is shown that the population transfer exceeds the coherence transfer significantly. That is
17th International School on Quantum Electronics: Laser Physics and Applications, 2013
The interest in quantum dots fluorescence is connected with the problem of implementing new prote... more The interest in quantum dots fluorescence is connected with the problem of implementing new protective luminescence markers and labels. We studied the luminescence spectra of multi-sized quantum dots fluorescent labels and quantum dots fluorescent labels with different matrix pore size.
2003 European Quantum Electronics Conference. EQEC 2003 (IEEE Cat No.03TH8665)
In this work the amplitude and width of the coherent resonances at the degenerate two-level syste... more In this work the amplitude and width of the coherent resonances at the degenerate two-level system on the (F8 = 2 → Fe = 1) transition at 87Rb D1 line have been investigated by means of Hanle effect configuration. A complex shape of the dark resonance was measured, the resonance curve consists of two parts: very narrow resonance centered at zero magnetic field superimposed on a broader one. The resonances are interesting for high-resolution spectroscopy and application in magnetometry.
SPIE Proceedings, 2008
... Emilia A. Alipieva ∗ , Elena T. Taskova, Sanka V. Gateva and Georgi Tz. ... 15th Internationa... more ... Emilia A. Alipieva ∗ , Elena T. Taskova, Sanka V. Gateva and Georgi Tz. ... 15th International School on Quantum Electronics: Laser Physics and Applications, edited by Tanja Dreischuh Elena Taskova, Ekaterina Borisova, Alexander Serafetinides, Proceedings of SPIE Vol. ...
Proceedings of the Second International Symposium of Trans Black Sea Region on Applied Electromagnetism (Cat. No.00TH8519), 2000
Summary form only given. We investigated the hidden alignment of Ne plasma in a magnetic field ob... more Summary form only given. We investigated the hidden alignment of Ne plasma in a magnetic field observing the optical characteristics of the medium-absorption and refraction. A tunable single frequency laser beam was used as a probe beam. Depending on the direction of the applied magnetic field and the geometry of observation the dependence of the plasma birefringence or dichroism on the magnetic field was registered.
SPIE Proceedings, 2003
Coherent population trapping (CPT) resonances in the degenerate two-level system of the F = 2 → F... more Coherent population trapping (CPT) resonances in the degenerate two-level system of the F = 2 → F = 1) transition of the Rb D line were investigated in an uncoated vacuum cell by means of Hanle effect configuration. CPT signals with complex shape (narrow resonance ...
ABSTRACT In this communication we present an investigation of the influence of an alternative mag... more ABSTRACT In this communication we present an investigation of the influence of an alternative magnetic field (a.c.MF) on the Coherent Population Trapping (CPT) resonances obtained in Hanle configuration. A.c.MF applied parallel to the sweeping magnetic field creates side-bands of the CPT resonance 1. Their position in dependence on the a.c.MF frequency and amplitude were investigated. This phenomenon was studied for the cases of linear and circular polarized laser excitation. Coherent signal due to the hexadecapole momentum created was detected. At high amplitudes of the a.c.MF alignment to orientation conversion was recorded.
Eighth International Conference on Laser and Laser Information Technologies, 2004
ABSTRACT
16th International School on Quantum Electronics: Laser Physics and Applications, 2010
ABSTRACT Modulated optical reflectance (MOR) technique is employed for defectoscopy and structura... more ABSTRACT Modulated optical reflectance (MOR) technique is employed for defectoscopy and structural analysis of La2/3Sr1/3MnO3(LSMO) ferromagnetic nanolayers. The optical reflectance is affected by the change of free charge carrier density due to periodic photothermal modulation described by Drude effect. A dual wavelength setup of a pulsed heating laser and a probe CW laser, whereas the laser focal spots are precisely aligned on the scanned sample surface, provides electrical signal proportional to the variation of optical reflectance at each measurement point. The probe beam is modulated selectively by reflection without interference by the substrate properties or external fields. It is shown theoretically and experimentally that MOR signal is proportional to the thermal derivative of magnetoresistance. The described contactless measurement may find important application in investigation of a range of new magnetoelectric devices.
13th International School on Quantum Electronics: Laser Physics and Applications, 2005
The purpose of this communication is to summarize and compare the results obtained under the proj... more The purpose of this communication is to summarize and compare the results obtained under the project" New all-optical systems and methods for magnetic and electromagnetic field measurement", financed by EC (contract G6RD-CT-2001-000642). The main aim of the ...
Optics and Spectroscopy, Sep 1, 1997
Journal of Physics: Conference Series, 2021
We review three laser spectroscopy schemes developed recently for observation of high-contrast en... more We review three laser spectroscopy schemes developed recently for observation of high-contrast enhanced-absorption nonlinear resonances in small alkali-vapor cells. In our experiments, optical transitions within the cesium D1 line are involved and a probe beam transmission is analyzed. The first spectroscopy method is based on the configuration with two-frequency counter propagating beams, which are linearly polarized in orthogonal directions. This configuration provides observation of high-contrast natural-linewidth resonances superimposed on broad Doppler profiles when the laser frequency is scanned. These resonances have good prospects for developing a miniature optical frequency reference. The second scheme involves two-frequency counter propagating beams with equal circular polarizations and provides observation of subnatural-linewidth resonances when the Raman frequency detuning is scanned. We use these resonances for stabilizing the microwave frequency of a local oscillator (...
Journal of Physics: Conference Series, 2020
We present an experimental investigation of electromagnetically-induced absorption (EIA) at the D... more We present an experimental investigation of electromagnetically-induced absorption (EIA) at the D1 line of 87Rb contained in an anti-relaxation coated vacuum optical cell. The configuration includes a pump and a probe beam propagating in opposite directions and having mutually orthogonal linear polarizations; the probe beam absorption is registered depending on the value of a magnetic field scanned around zero and applied collinearly to the laser beams. The advantages of this scheme have been recently evidenced in vapor cells filled with a buffer gas. In the present work we studied the width and the contrast of the EIA resonances obtained in a coated cell for different values of the pump power. The results are compared with those obtained in a buffer gas cell for the same transition of 87Rb. The theoretical calculations are in good agreement with the experiment.
Optics and Spectroscopy, 2019
The nonlinear Hanle effect is generally considered in the modern literature as a particular case ... more The nonlinear Hanle effect is generally considered in the modern literature as a particular case of coherent population trapping (CPT) at degenerate Zeeman sublevels of the ground atomic state. The shape, amplitude, and sign of observed resonances and their dependence on the excitation parameters and observation geometry were investigated theoretically and experimentally in many studies because of the wide range of application of this effect. The sensitivity of Hanle resonances to the experimental conditions increases significantly in cells with antirelaxation coating, because the atomic ensemble retains its coherence after a large number of collisions with the cell walls. In this paper, the main attention is paid to the joint influence of the excitation radiation intensity and spurious magnetic fields on CPT resonances observed in fluorescence. The theoretical description is based on the numerical solution of an algebraic system of equations for density matrix in the formalism of irreducible tensor operators. The parameters relating different polarization moments in each equation are visualized using the modified sparse matrix of the system. It is established by numerical simulation that the shape, width, amplitude, and sign of nonlinear magnetooptical resonances change nonmonotonically with a change in the parameters of the excitation radiation and atomic system. The presented theoretical results are in good agreement with the experimental data obtained under various conditions.
SPIE Proceedings, 2016
COSMA-Coherent Optics Sensors for Medical Application is an European Marie Curie Project running ... more COSMA-Coherent Optics Sensors for Medical Application is an European Marie Curie Project running from 2012 to March 2016, with the participation of 10 teams from Armenia,
The ultra narrow resonances, obtained by means of polarization spectroscopy of alkali atoms, orig... more The ultra narrow resonances, obtained by means of polarization spectroscopy of alkali atoms, originate from the destruction of the laser-induced coherence in the ground state. In the case of single-frequency, near resonance excitation and suitable geometry the well-known ground state Hanle effect is observed. Coherent population trapping in Hanle configuration is a nonlinear modification of this effect, observed in the fluorescence from the upper level. The ground state coherence is transmitted from the laser field and higher rank polarization moments are created. Using the irreducible tensor operator formalism programs for numerical modelling of this effect has been developed and presented here. The velocity distribution of the atoms, the Gaussian distribution of the laser beam, stray magnetic field, and the experimental geometry are taken into account. The scheme of conversion of the octupole (κ = 3) and hexadecapole (κ = 4) polarization moments (PM) through the laser and magnetic fields into the upper level quadropoles f 2 q is proposed. The conversion of the high-rank polarization moments (PM) into observable components is also discussed. The results of the modelling are compared with the measured ones at different experimental conditions.
A theoretical description is given of interference effects in the spontaneous emission from a cas... more A theoretical description is given of interference effects in the spontaneous emission from a cascade laser, i.e., a laser operating on successively coupled transitions. The kinetic equation of a cascade laser in a magnetic field is considered, and a description is given of depolarization signals and the related anisotropy of spontaneous emission. General expressions are obtained which can be used
Journal of the Optical Society of America A, 1990
An experimental investigation of spectral dependence of two recently discovered anomalies in deep... more An experimental investigation of spectral dependence of two recently discovered anomalies in deep metallic gratings is presented. Good coincidence with theoretical results is obtained. It is shown that the Brewster effect in deep gratings is suppressed with a decrease of wavelength, as the angle of incidence approaches zero. At the same time the groove-depth interval widens, and low values of reflectivity are observed.
Journal of Physics B: Atomic and Molecular Physics, 1985
This paper presents a theoretical investigation of some peculiarities of alignment signals from l... more This paper presents a theoretical investigation of some peculiarities of alignment signals from laser levels carried out in simultaneous oscillation of two transitions connected by spontaneous emission. An expression is obtained for a spontaneous emission part caused by the oscillation originating from the lower laser level. It is shown that the population transfer exceeds the coherence transfer significantly. That is
17th International School on Quantum Electronics: Laser Physics and Applications, 2013
The interest in quantum dots fluorescence is connected with the problem of implementing new prote... more The interest in quantum dots fluorescence is connected with the problem of implementing new protective luminescence markers and labels. We studied the luminescence spectra of multi-sized quantum dots fluorescent labels and quantum dots fluorescent labels with different matrix pore size.
2003 European Quantum Electronics Conference. EQEC 2003 (IEEE Cat No.03TH8665)
In this work the amplitude and width of the coherent resonances at the degenerate two-level syste... more In this work the amplitude and width of the coherent resonances at the degenerate two-level system on the (F8 = 2 → Fe = 1) transition at 87Rb D1 line have been investigated by means of Hanle effect configuration. A complex shape of the dark resonance was measured, the resonance curve consists of two parts: very narrow resonance centered at zero magnetic field superimposed on a broader one. The resonances are interesting for high-resolution spectroscopy and application in magnetometry.
SPIE Proceedings, 2008
... Emilia A. Alipieva ∗ , Elena T. Taskova, Sanka V. Gateva and Georgi Tz. ... 15th Internationa... more ... Emilia A. Alipieva ∗ , Elena T. Taskova, Sanka V. Gateva and Georgi Tz. ... 15th International School on Quantum Electronics: Laser Physics and Applications, edited by Tanja Dreischuh Elena Taskova, Ekaterina Borisova, Alexander Serafetinides, Proceedings of SPIE Vol. ...
Proceedings of the Second International Symposium of Trans Black Sea Region on Applied Electromagnetism (Cat. No.00TH8519), 2000
Summary form only given. We investigated the hidden alignment of Ne plasma in a magnetic field ob... more Summary form only given. We investigated the hidden alignment of Ne plasma in a magnetic field observing the optical characteristics of the medium-absorption and refraction. A tunable single frequency laser beam was used as a probe beam. Depending on the direction of the applied magnetic field and the geometry of observation the dependence of the plasma birefringence or dichroism on the magnetic field was registered.
SPIE Proceedings, 2003
Coherent population trapping (CPT) resonances in the degenerate two-level system of the F = 2 → F... more Coherent population trapping (CPT) resonances in the degenerate two-level system of the F = 2 → F = 1) transition of the Rb D line were investigated in an uncoated vacuum cell by means of Hanle effect configuration. CPT signals with complex shape (narrow resonance ...
ABSTRACT In this communication we present an investigation of the influence of an alternative mag... more ABSTRACT In this communication we present an investigation of the influence of an alternative magnetic field (a.c.MF) on the Coherent Population Trapping (CPT) resonances obtained in Hanle configuration. A.c.MF applied parallel to the sweeping magnetic field creates side-bands of the CPT resonance 1. Their position in dependence on the a.c.MF frequency and amplitude were investigated. This phenomenon was studied for the cases of linear and circular polarized laser excitation. Coherent signal due to the hexadecapole momentum created was detected. At high amplitudes of the a.c.MF alignment to orientation conversion was recorded.
Eighth International Conference on Laser and Laser Information Technologies, 2004
ABSTRACT
16th International School on Quantum Electronics: Laser Physics and Applications, 2010
ABSTRACT Modulated optical reflectance (MOR) technique is employed for defectoscopy and structura... more ABSTRACT Modulated optical reflectance (MOR) technique is employed for defectoscopy and structural analysis of La2/3Sr1/3MnO3(LSMO) ferromagnetic nanolayers. The optical reflectance is affected by the change of free charge carrier density due to periodic photothermal modulation described by Drude effect. A dual wavelength setup of a pulsed heating laser and a probe CW laser, whereas the laser focal spots are precisely aligned on the scanned sample surface, provides electrical signal proportional to the variation of optical reflectance at each measurement point. The probe beam is modulated selectively by reflection without interference by the substrate properties or external fields. It is shown theoretically and experimentally that MOR signal is proportional to the thermal derivative of magnetoresistance. The described contactless measurement may find important application in investigation of a range of new magnetoelectric devices.
13th International School on Quantum Electronics: Laser Physics and Applications, 2005
The purpose of this communication is to summarize and compare the results obtained under the proj... more The purpose of this communication is to summarize and compare the results obtained under the project" New all-optical systems and methods for magnetic and electromagnetic field measurement", financed by EC (contract G6RD-CT-2001-000642). The main aim of the ...