109 results on '"Vitaly V. Samartsev"'
Search Results
2. Exciton Nutation in a Layer of Semiconductor Quantum Dots
- Author
-
T. G. Mitrofanova, Vitaly V. Samartsev, and O. Kh. Khasanov
- Subjects
010302 applied physics ,Physics::General Physics ,Materials science ,Condensed matter physics ,Condensed Matter::Other ,010308 nuclear & particles physics ,Exciton ,Nutation ,Hadron ,Thin layer ,General Physics and Astronomy ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,01 natural sciences ,Physics::Geophysics ,Condensed Matter::Materials Science ,Semiconductor quantum dots ,0103 physical sciences ,Layer (electronics) - Abstract
The possibility of observing the exciton nutation in a thin layer of CdSe/CdS/ZnS semiconductor quantum dots is demonstrated theoretically.
- Published
- 2019
3. Determining the Pseudo-Stark Coefficient in Y2SiO5:Er3+ from the Photon Echo Oscillations and Beats upon a 4F9/2–4I15/2 Transition
- Author
-
V. N. Lisin, A. M. Shegeda, and Vitaly V. Samartsev
- Subjects
Physics ,Photon ,Hadron ,Echo (computing) ,Physics::Optics ,General Physics and Astronomy ,01 natural sciences ,Ion ,010309 optics ,Matrix (mathematics) ,Amplitude ,Optical frequencies ,Electric field ,0103 physical sciences ,Atomic physics ,010306 general physics - Abstract
The pseudo-Stark shift in the optical frequency of the 4F9/2–4I15/2 transition of an Er3+ ion in a Y2SiO5 matrix under the action of a weak pulsed electric field is measured from changes in the amplitude and temporal shape of the photon echo.
- Published
- 2018
4. Theoretical Study of the Possibility of Creating a Quantum Gate and Exciton Coherence on Semiconductor Quantum Dots
- Author
-
Vitaly V. Samartsev, D. I. Kamalova, and T. G. Mitrofanova
- Subjects
Condensed Matter::Quantum Gases ,010302 applied physics ,Physics ,Condensed Matter::Other ,Exciton ,Hadron ,General Physics and Astronomy ,Coherence (statistics) ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,01 natural sciences ,010309 optics ,Condensed Matter::Materials Science ,Quantum gate ,Semiconductor quantum dots ,Quantum dot ,Quantum mechanics ,0103 physical sciences - Abstract
The possibility of and conditions for creating a quantum gate and exciton coherence on semiconductor quantum dots are investigated theoretically. Prospects for observing exciton echoes on quantum dots are discussed.
- Published
- 2018
5. Oscillations of Light during a Photon Echo: Observation and Application
- Author
-
V. N. Lisin, Vitaly V. Samartsev, and A. M. Shegeda
- Subjects
Physics ,Photon ,Zeeman effect ,Hadron ,Echo (computing) ,Echo signal ,General Physics and Astronomy ,Perturbation (astronomy) ,01 natural sciences ,Ion ,010309 optics ,symbols.namesake ,0103 physical sciences ,symbols ,Atomic physics ,010306 general physics ,Spectroscopy - Abstract
An ultra high-resolution optical spectroscopy technique is proposed for measuring Zeeman and pseudo-Stark frequency splitting during optical transitions. This approach uses the change in the time shape of the echo signal upon a a weak pulse perturbation that splits the optical transition frequencies of two or more echo-active ion subgroups.
- Published
- 2018
6. Selective Spectroscopy Based on the Multiple-Pulse Excitation of the Ultrafast Optical Kerr Effect
- Author
-
Vladimir S. Lobkov, Victor G. Nikiforov, and Vitaly V. Samartsev
- Subjects
Materials science ,Kerr effect ,business.industry ,Physics::Optics ,General Physics and Astronomy ,Laser ,01 natural sciences ,law.invention ,010309 optics ,Molecular dynamics ,law ,0103 physical sciences ,Optoelectronics ,Molecule ,Multiple pulse ,010306 general physics ,business ,Spectroscopy ,Ultrashort pulse ,Excitation - Abstract
The use of multiple-pulse laser excitation to control molecular responses that produce the ultrafast optical Kerr effect in order to perform selective spectroscopy of the Raman-active motions of molecules in liquids is discussed. Theoretical analysis and experimental data indicate that multiple-pulse laser excitation is a powerful spectroscopic tool that allows unique information to be obtained about low-frequency molecular dynamics in a liquid.
- Published
- 2018
7. Effect of the Excitation Radiation Coherence on Oscillations of the Photon Echo Intensity
- Author
-
A. M. Shegeda, Vitaly V. Samartsev, E. P. Chukalina, and V. N. Lisin
- Subjects
Physics ,Photon ,Zeeman effect ,Physics and Astronomy (miscellaneous) ,Degree of coherence ,Magnetostatics ,01 natural sciences ,Magnetic field ,010309 optics ,symbols.namesake ,Amplitude ,0103 physical sciences ,symbols ,Atomic physics ,010306 general physics ,Excitation ,Coherence (physics) - Abstract
The physical reasons for observing the splitting of optical lines several orders of magnitude smaller than the spectral width of a laser pulse are investigated. A theory of coherent and incoherent photon echo (PE) in an external static magnetic field and in the presence of a pulsed magnetic field, which causes oscillations of the PE intensity, is elaborated. It is shown that the periods of oscillations in the echo intensity, the echo duration, and the dimensions of the regions in the inhomogeneous line, where the excited ions are coherent, do not depend on the degree of coherence of the laser pulse and on the external static magnetic field. As follows from the theory, in the case of the coherent excitation of the echo, the amplitude of the intensity oscillations is independent of the external static magnetic field if the inhomogeneous line is symmetric. It is shown that the amplitude of the oscillations at the incoherent excitation of the echo is equal to the autocorrelation function of the distribution function of the transition frequency along the inhomogeneous line with the argument equal to the Zeeman splitting of the optical line in the external magnetic field. In this case, the experimental values of the oscillation amplitude are in good agreement with the calculated values of the autocorrelation function for the total inhomogeneous line in LuLiF4:Er3+ (4I15/2⇒F9/2 transition). In the same way, the autocorrelation function has been obtained for YLiF4:Er3+ on the same transition.
- Published
- 2018
8. Ultrafast Relaxation of Photocarriers in Cadmium Sulfide
- Author
-
A. V. Leontyev, Vladimir S. Lobkov, A. G. Shmelev, Vitaly V. Samartsev, and D. K. Zharkov
- Subjects
Materials science ,genetic structures ,Relaxation (NMR) ,Physics::Optics ,General Physics and Astronomy ,Grating ,Molecular physics ,Cadmium sulfide ,Condensed Matter::Materials Science ,chemistry.chemical_compound ,chemistry ,Picosecond ,Femtosecond ,Charge carrier ,Single crystal ,Refractive index - Abstract
Experiments are performed on registering induced changes in the refractive index of a cadmium sulfide single crystal with femtosecond time resolution in the transient lens and transient gratings geometries. The lifetime of photoexcited charge carriers (photocarriers) is estimated at 230 ps. An additional component, characterized by a decay time of units of picoseconds, is found in the efficiency decay of the transient grating of free carrier concentration. It is shown that this time is determined by the thermalization rate of photocarriers.
- Published
- 2019
9. Modeling the Induction of Excitons upon the Continuous-Wave Laser Excitation of an Ensemble of Semiconductor Quantum Dots
- Author
-
O. Kh. Khasanov, T. G. Mitrofanova, and Vitaly V. Samartsev
- Subjects
010302 applied physics ,Materials science ,Condensed Matter::Other ,010308 nuclear & particles physics ,Exciton ,Thin layer ,Hadron ,General Physics and Astronomy ,Radiation ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Laser ,01 natural sciences ,law.invention ,Condensed Matter::Materials Science ,Semiconductor quantum dots ,law ,0103 physical sciences ,Continuous wave ,Atomic physics ,Excitation - Abstract
A theoretical investigation is performed for the possibility and conditions of the stimulated induction of excitons in a thin layer of semiconductor quantum dots upon excitation by continuous-wave laser radiation.
- Published
- 2020
10. Ultrafast spectroscopy of CdS/CdSe quantum dots
- Author
-
D. K. Zharkov, Vladimir S. Lobkov, Victor G. Nikiforov, A. V. Leontyev, A. G. Shmelev, and Vitaly V. Samartsev
- Subjects
Materials science ,Physics::Optics ,General Physics and Astronomy ,Nanoparticle ,02 engineering and technology ,01 natural sciences ,Signal ,law.invention ,Condensed Matter::Materials Science ,Optics ,law ,0103 physical sciences ,Spectroscopy ,Envelope (waves) ,010302 applied physics ,Condensed Matter::Other ,business.industry ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,021001 nanoscience & nanotechnology ,Computer Science::Other ,Lens (optics) ,Amplitude ,Quantum dot ,Optoelectronics ,0210 nano-technology ,business ,Ultrashort pulse - Abstract
Results from the nonresonance spectroscopy of CdS/CdSe quantum dots (composites of CdSe–CdS nanoparticles (core–shell)) are presented. The nonlinear optical properties of CdS/CdSe QDs in PMMA are studied with fs pulses at 1053 nm using the transient lens technique. QDs generate rapidly oscillating signals with amplitude rise times of around 200 fs and decay times of around 500 fs, while pure PMMA polymer only generates an oscillating signal whose envelope coincides with its autocorrelation function.
- Published
- 2017
11. Effect of Quantum Size on the Luminescent Properties of Quantum Dots Based on Cadmium Halcogenides
- Author
-
A. V. Leontyev, Vladimir S. Lobkov, D. K. Zharkov, R. R. Shamilov, I. V. Kryukov, A. G. Shmelev, Vitaly V. Samartsev, and Victor G. Nikiforov
- Subjects
010302 applied physics ,Nanocomposite ,Materials science ,General Physics and Astronomy ,Nanoparticle ,Photochemistry ,01 natural sciences ,Fluorescence ,Colloid ,Quantum dot ,0103 physical sciences ,Femtosecond ,010306 general physics ,Spectroscopy ,Luminescence - Abstract
The quantum size effects of colloid water-organic media synthesized nanocomposites (CdSe–CdS core–shell) in toluene solution is studied. Femtosecond fluorescence up-conversion spectroscopy is used to establish that quantum dots are characterized by a biexponential decay of luminescence kinetics: the decay times are 1.8 and 26.8 ps for nanoparticles with average sizes of 2 nm and 4.5, and 68 ps for nanoparticles with an average size of 2.9 nm.
- Published
- 2018
12. Partially coherent photon echo in the presence of pulsed and static magnetic fields
- Author
-
A. M. Shegeda, Vitaly V. Samartsev, and Valery Lisin
- Subjects
Physics ,History ,Photon ,Optics ,business.industry ,Echo (computing) ,business ,Computer Science Applications ,Education ,Magnetic field - Abstract
The theory of a partially coherent photon echo in a static magnetic field at the presence of a pulsed magnetic field, causing oscillations of the echo intensity, is constructed. It is shown that the coherence time can be found by the dependence of the echo intensity on the laser frequency. The theory is compared with the experiment in LuLiF4:Er3+ (transition 4I15/2 -4F9/2) and in YLiF4:Er3+ at the same transition.
- Published
- 2020
13. Monitoring of the luminescence properties of the upconversion YVO4:Yb, Er nanoparticles during preparation processes
- Author
-
Vladimir S. Lobkov, A. V. Leontyev, Aleksei M. Zheltikov, Ilya V. Fedotov, Masfer Alkahtani, Philip R. Hemmer, D. K. Zharkov, Victor G. Nikiforov, I Z Latypov, A. G. Shmelev, and Vitaly V. Samartsev
- Subjects
History ,Materials science ,Fabrication ,business.industry ,Doping ,Nanoparticle ,Laser ,Photon upconversion ,Computer Science Applications ,Education ,law.invention ,Photoexcitation ,law ,Optoelectronics ,business ,Luminescence ,Spectroscopy - Abstract
We have fabricated the upconversion nanoparticles (NPs), which are nanocrystallites of 10 nm, doped with Yb3+ and Er3+ ions, prepared through hydrothermal method. Monitoring of their photophysical properties had been realized at different fabrication stages by using electron microscopy and luminescence spectroscopy under photoexcitation of the NPs with the 100 mW laser at 980 nm wavelength. The performed monitoring allows us to observe dramatic changes in the upconversion properties of the NPs during the sequence of the fabrication stages and revealed very strong correlation between the NPs’ upconversion efficiency and their structural specificities.
- Published
- 2020
14. Light converting Yb3+/Er3+ doped YVO4 nanoparticles for biological applications
- Author
-
Masfer Alkahtani, Vladimir S. Lobkov, A. V. Leontyev, Victor G. Nikiforov, D. K. Zharkov, Philip R. Hemmer, A. G. Shmelev, and Vitaly V. Samartsev
- Subjects
Materials science ,Physics and Astronomy (miscellaneous) ,Doping ,Nanoparticle ,Nanotechnology ,Instrumentation - Published
- 2020
15. Femtosecond coherent spectroscopy of four-wave mixing and the spectroscopy of transient gratings in GaAs/AlGaAs semiconductor heterostructures at room temperature
- Author
-
T. G. Mitrofanova, A. V. Leontyev, Vitaly V. Samartsev, O. Kh. Khasanov, and K. V. Ivanin
- Subjects
Materials science ,Spins ,Spintronics ,Condensed Matter::Other ,business.industry ,General Physics and Astronomy ,Heterojunction ,Electron ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Condensed Matter::Materials Science ,Four-wave mixing ,Femtosecond ,Optoelectronics ,business ,Coherent spectroscopy ,Spectroscopy - Abstract
Results from femtosecond coherent spectroscopy of four-wave mixing in GaAs/AlGaAs semiconductor heterostructures at room temperature are presented. Electron diffusivities and their spins are found via spectroscopy of transient gratings. Investigations in the field of spin transport in GaAs/AlGaAs heterostructures are performed with the aim of their possible use in spintronics applications.
- Published
- 2014
16. Photoinduced carrier dynamics in colloidal CdSe/CdS nanoparticles
- Author
-
D. K. Zharkov, Victor G. Nikiforov, A. G. Shmelev, Vitaly V. Samartsev, A. V. Leontyev, and Vladimir S. Lobkov
- Subjects
History ,Materials science ,Nanoparticle ,Laser ,Computer Science Applications ,Education ,law.invention ,Chemical physics ,law ,Picosecond ,Excited state ,Femtosecond ,Charge carrier ,Spectroscopy ,Luminescence - Abstract
We have studied picosecond dynamics of photo-induced charge carriers in CdSe/CdS nanoparticles with sizes of 2.0 and 2.9 nm in toluene colloidal solutions using femtosecond up-conversion spectroscopy. The kinetics of nanoparticles luminescence excited by laser pulses of 50 fs duration at 350 nm were observed. The simulation of experimental data showed that electron thermalization occurs within 0.5 ps, while recombination processes have characteristic times of 5 and 20 ns, although these cannot be unequivocally identified using the simplest recombination model with direct transitions and single type of traps. However, a comparative analysis indicates a fundamental difference in the mechanisms responsible for the dynamics of charge carriers in the time interval up to 5 ps after laser excitation, which we associate with different structures of traps in 2.0 and 2.9 nm particles.
- Published
- 2019
17. Luminescence properties of YVO4:Yb,Er nanoparticles dispersed in water
- Author
-
Philip R. Hemmer, D. K. Zharkov, A P Saiko, A. V. Leontyev, Vladimir S. Lobkov, Victor G. Nikiforov, N M Lyadov, A. G. Shmelev, and Vitaly V. Samartsev
- Subjects
History ,Materials science ,Aqueous solution ,Quenching (fluorescence) ,Excited state ,Femtosecond ,Nanoparticle ,Luminescence ,Photochemistry ,Spectral line ,Computer Science Applications ,Education ,Ion - Abstract
We have synthesized YVO4: Yb, Er nanoparticles in the size range of 100-500 nm, which form aqueous colloidal solutions and are luminescent when excited by femtosecond light pulses at a wavelength of 263 nm. It was established that the luminescence occurs due to the emission of Er3+ ions in characteristic spectral lines at 525 nm and 550 nm. However, an effective quenching channel for metastable levels of Er3+ ions is evident, so that the characteristic luminescence line of Er3+ ions in the 660 nm region is absent. We associate this quenching channel with a large concentration of lattice defects with possible localization of high-frequency quenchers.
- Published
- 2019
18. Ultrafast photoinduced charge dynamics in colloidal CdSe/CdS quantum dots in toluene
- Author
-
Victor G. Nikiforov, Vladimir S. Lobkov, D. K. Zharkov, A. G. Shmelev, Vitaly V. Samartsev, and A. V. Leontyev
- Subjects
Materials science ,Physics and Astronomy (miscellaneous) ,Charge (physics) ,Core shell nanoparticles ,Toluene ,chemistry.chemical_compound ,Colloid ,chemistry ,Quantum dot ,Chemical physics ,Femtosecond laser spectroscopy ,Charge carrier ,Instrumentation ,Ultrashort pulse - Published
- 2019
19. Incoherent exciton echo on the CdSe/CdS/ZnS semiconductor quantum dots
- Author
-
T. G. Mitrofanova, Alexander P. Saiko, and Vitaly V. Samartsev
- Subjects
010302 applied physics ,Materials science ,Condensed Matter::Other ,business.industry ,Physics ,QC1-999 ,Exciton ,Echo (computing) ,Thin layer ,Substrate (electronics) ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,01 natural sciences ,Condensed Matter::Soft Condensed Matter ,010309 optics ,Condensed Matter::Materials Science ,Semiconductor quantum dots ,0103 physical sciences ,Optoelectronics ,business ,Excitation - Abstract
The possibility and conditions of an incoherent exciton echo excitation in a thin layer of the CdSe/CdS/ZnS semiconductor quantum dots spread on a glass substrate are discussed.
- Published
- 2019
20. Entangled femtosecond free induction signals in a cadmium sulfide crystal at room temperature
- Author
-
A. V. Leontiev, A. G. Shmelyov, Vitaly V. Samartsev, T. G. Mitrofanova, and Vladimir S. Lobkov
- Subjects
Materials science ,business.industry ,Physics::Optics ,General Physics and Astronomy ,Cadmium sulfide ,Crystal ,Free induction decay ,Wavelength ,Polarization density ,chemistry.chemical_compound ,Optics ,chemistry ,Femtosecond ,Atomic physics ,business ,Absorption (electromagnetic radiation) ,Excitation - Abstract
Entangled free induction decay (EFID) femtosecond signals are experimentally observed for the first time at a wavelength of 790 nm in a cadmium sulfide (CdS) crystal in the two-photon absorption (TPA) regime upon excitation by two crossed (angle, 60°) laser beams. The sample emitted two EFID signals simultaneously in opposite directions. The signals were diffracted by nonequilibrium electric polarization gratings induced by two laser beams in accordance with the laws of energy and momentum conservation. The possibility of exciting EFID signals in the three-photon absorption regime is discussed.
- Published
- 2012
21. The application of the weak electric field pulse to measure the pseudo-Stark split by the photon echo beating
- Author
-
V. N. Lisin, A. M. Shegeda, and Vitaly V. Samartsev
- Subjects
Physics ,Condensed Matter - Materials Science ,Photon ,Physics and Astronomy (miscellaneous) ,Condensed Matter - Mesoscale and Nanoscale Physics ,Echo (computing) ,Inverse ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,01 natural sciences ,Measure (mathematics) ,010309 optics ,Modulation ,Computer Science::Sound ,Excited state ,Electric field ,0103 physical sciences ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Waveform ,Atomic physics ,010306 general physics ,Instrumentation - Abstract
A novel scheme for determining the pseudo-Stark splitting of optical lines has been suggested and tested in experiment. The scheme allows one to observe the beating of a photon echo waveform under conditions of overlap in time between a weak electric pulse and its echo- pulse. The pseudo-Stark splitting is equal to the inverse average modulation period of the echo waveform. The photon echo beating of the R1-line in Ruby has been observed. The dependence of the inverse average modulation period of the echo waveform on the average value of the electric field over the optically excited volume has been found. The obtained values of the pseudo-Stark parameter are in good agreement with known literature data., 4 pages, 4 figures, 8 references, Laser Physics Letters, Volume 13, Number 7
- Published
- 2016
22. 'Entangled' free-induction decay in CdS crystal under two-photon excitation by two crossed laser beams
- Author
-
A. V. Leontiev, Vladimir S. Lobkov, T. G. Mitrofanova, Vitaly V. Samartsev, and A. G. Shmelyov
- Subjects
Physics ,Photon ,Physics and Astronomy (miscellaneous) ,business.industry ,Physics::Optics ,Signal ,Free induction decay ,Crystal ,Wavelength ,Optics ,Two-photon excitation microscopy ,Femtosecond ,Atomic physics ,business ,Instrumentation ,Excitation - Abstract
A new method of two-photon excitation of femtosecond signals of ``entangled'' free induction decay (EFID) by two crossed 790-nm laser beams in a CdS crystal at room temperature has been realized for the first time. This ``entangled'' (through the wave vectors) coherent response appears only in the case when the photons involved to the process of two-photon excitation of the sample belong to the different laser beams. This technique allows one to separate the EFID signal from the exciting femtosecond pulses and to vary the response wavelength by varying the angle between their wave vectors. The most optimal case occurs when the angle between the wave vectors of exciting pulses as well as the angle between each of these wave vectors and that of the response is equal to 60°.
- Published
- 2012
23. Femtosecond laser control of intramolecular vibrations in a liquid
- Author
-
A. G. Shmelev, Vitaly V. Samartsev, Vladimir S. Lobkov, Victor G. Nikiforov, and G. M. Safiullin
- Subjects
Kerr effect ,Materials science ,business.industry ,Linear polarization ,Physics::Optics ,General Physics and Astronomy ,Laser ,Polarization (waves) ,law.invention ,Optics ,law ,Intramolecular force ,Femtosecond ,Physics::Chemical Physics ,Atomic physics ,Spectroscopy ,business ,Excitation - Abstract
Optical control of coherent intramolecular oscillations in chloroform CHCl3 and dimethyl sulfoxide (CH3)2SO is attained experimentally under normal conditions by means of femtosecond polarization spectroscopy. Nonresonant excitation of the medium is accomplished by a sequence of two linearly polarized laser pulses. The state of the medium is probed by the third pulse via the optical Kerr effect. We show that control over the vibrational dynamics of molecules on a sub-picosecond scale can be achieved by varying the delay between the excitation pulses and their relative intensity.
- Published
- 2012
24. Simulation of coherent responses of resonant media excited by a series of ultrashort laser pulses
- Author
-
Alexey Tiranov, K. R. Karimullin, and Vitaly V. Samartsev
- Subjects
Physics ,Photon ,Computer simulation ,business.industry ,Finite-difference time-domain method ,Physics::Optics ,General Physics and Astronomy ,Resonance ,Laser ,law.invention ,Pulse (physics) ,Optics ,law ,Femtosecond ,business ,Envelope (waves) - Abstract
A technique for the numerical simulation of coherent optical responses of the photon echo type formed in resonance media with strong inhomogeneous broadening under the action of femtosecond laser pulses is developed. This approach is based on solving the Maxwell-Bloch equations using the finite-difference time-domain (FDTD) method without application of a fast rotating field and slowly varying envelope approximations. The method can be used to simulate coherent responses in different resonance media with a complex structure of energy levels. The technique was validated using the example of describing experiments on narrowing a photon echo pulse and femtosecond echo processing.
- Published
- 2012
25. Femtosecond coherent spectroscopy of four-wave mixing and photon echoes in a GaAs/AlGaAs heterostructure at room temperature
- Author
-
Vitaly V. Samartsev, Vladimir S. Lobkov, G. M. Safiullin, K. V. Ivanin, and A. V. Leont’ev
- Subjects
Photon ,Materials science ,Spintronics ,business.industry ,Dephasing ,General Physics and Astronomy ,Heterojunction ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Condensed Matter::Materials Science ,Four-wave mixing ,Semiconductor ,Femtosecond ,Optoelectronics ,Atomic physics ,business ,Coherent spectroscopy - Abstract
The results from experiments employing coherent femtosecond spectroscopy in a layer of two-dimensional electron gas at the boundary of the GaAs/AlGaAs heterojunction at room temperature are presented. The decay curves of primary femtosecond photon echo are obtained. The decoherence time in two-dimensional electron gas depends strongly on the power of the exciting pulse and varies from 36 to 54 fs. The dephasing time is studied for the first time as a function of the power of exciting pulses at room temperature. It is established that this dependence obeys the law T 2 ∼ N −0.22, which differs from the typical law T 2 ∼ N −1 for unscreened electron-electron interaction in semiconductor crystals. Analysis shows that electron-phonon interaction plays an important part along with electron-electron interaction. The induced spin gratings in the GaAs/AlGaAs heterostructure are studied with an eye to their possible application in spintronics.
- Published
- 2012
26. Polarization tomography of a narrow-band biphoton field
- Author
-
A. E. Mihailov, Vitaly V. Samartsev, A. A. Kalinkin, A. V. Shkalikov, A. A. Kalachev, and I. Z. Latypov
- Subjects
Physics ,business.industry ,Hadron ,Physics::Optics ,General Physics and Astronomy ,Quantum tomography ,Polarization (waves) ,Waveplate ,law.invention ,Nonlinear system ,Optics ,law ,Optical cavity ,Tomography ,Physics::Chemical Physics ,business ,Quantum - Abstract
Narrow-band orthogonally polarized collinear frequency-degenerate biphotons are generated in the process of the spontaneous parametric down-conversion of light in a nonlinear BBO crystal placed in an optical resonator. Quantum polarization tomography and polarization transformation of the generated biphoton states are performed. The results from our experiment agree well with theoretical calculations.
- Published
- 2011
27. Polarization two-pulse method for analysis of sensing femtosecond signals based on the ultrafast optical Kerr effect
- Author
-
Vladimir S. Lobkov, G. M. Safiullin, Victor G. Nikiforov, A. G. Shmelev, and Vitaly V. Samartsev
- Subjects
Atmospheric Science ,Materials science ,Kerr effect ,business.industry ,Oceanography ,Polarization (waves) ,Laser ,Atomic and Molecular Physics, and Optics ,law.invention ,Optics ,law ,Femtosecond ,Photonics ,Spectroscopy ,Anisotropy ,business ,Ultrashort pulse ,Earth-Surface Processes - Abstract
A novel molecular polarization spectroscopy method of processing the strengthened femtosecond signals, based on the ultrafast optical Kerr effect, is proposed. The processing of the reference chloroform signal by the novel method at a room temperature is demonstrated. It is shown that due to the manipulation by individual molecular motions through the constructive or destructive interference of corresponding wave packets it is possible to determine directly from the experiment such constants of molecular dynamics as the relaxation times of the coherent vibrations (≈1.5 ps) and orientation anisotropy (≈1.2 ps).
- Published
- 2011
28. Femtosecond selective optical Kerr-effect spectroscopy: Molecular dynamics study of chloroform
- Author
-
A. G. Shmelev, Vitaly V. Samartsev, Vladimir S. Lobkov, G. M. Safiullin, and Victor G. Nikiforov
- Subjects
Kerr effect ,Materials science ,business.industry ,Relaxation (NMR) ,Nonlinear optics ,Condensed Matter Physics ,Molecular physics ,Industrial and Manufacturing Engineering ,Atomic and Molecular Physics, and Optics ,Molecular dynamics ,Optics ,Femtosecond ,Anisotropy ,business ,Spectroscopy ,Instrumentation ,Excitation - Abstract
The femtosecond selective spectroscopy of vibrational-rotational dynamics of molecules in a liquid was realized using optical Kerr effect registration under two-pulse nonresonant excitation. The object chosen for the study was the chloroform at room temperature. It was shown that control of the separate molecular motions by creating the constructive or destructive interference of corresponding wave packets allows one to determine directly from the experiment such constants of molecular dynamics as the relaxation times of the coherent vibrations (≈1.5 ps) and those of orientational anisotropy (≈1.2 ps).
- Published
- 2010
29. Luminescence kinetics of CdSe-based quantum dots in toluene
- Author
-
D. K. Zharkov, A. V. Leontyev, A. G. Shmelev, Vitaly V. Samartsev, Victor G. Nikiforov, and Vladimir S. Lobkov
- Subjects
History ,chemistry.chemical_compound ,Materials science ,chemistry ,Quantum dot ,Kinetics ,Photochemistry ,Luminescence ,Toluene ,Computer Science Applications ,Education - Published
- 2018
30. Femtosecond photon echo and four-wave mixing studies on GaAs/AlGaAs heterostructure at room temperature
- Author
-
A.V. Leontyev, Vladimir S. Lobkov, K. V. Ivanin, and Vitaly V. Samartsev
- Subjects
Photon ,Materials science ,Physics and Astronomy (miscellaneous) ,business.industry ,Dephasing ,Physics::Optics ,Nonlinear optics ,Heterojunction ,Electron ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Four-wave mixing ,Optics ,Femtosecond ,Atomic physics ,business ,Instrumentation ,Femtochemistry - Abstract
We report femtosecond photon echo and four-wave mixing measurements performed on GaAs/AlGaAs heterostructure at room temperature. In femtosecond photon echo experiment the dephasing time was obtained, found to vary between 40 and 55 fs depending on carrier density. The dependence showed a power-law behavior T2 ∝ N-0.22, which indicates that major phase coherence loss is due to screened Coulomb electron-electron interaction. Transient grating experiments yielded the electron diffusion coefficient value of 200 cm2/s and electron relaxation time equal to 3 ns.
- Published
- 2010
31. Coherent optical spectroscopy of promising materials for solid-state optical processors
- Author
-
Vitaly V. Samartsev
- Subjects
Materials science ,business.industry ,Doping ,Echo (computing) ,Physics::Optics ,Laser science ,Condensed Matter Physics ,Laser ,Industrial and Manufacturing Engineering ,Atomic and Molecular Physics, and Optics ,law.invention ,Optics ,law ,Femtosecond ,Photonics ,Coherent spectroscopy ,business ,Spectroscopy ,Instrumentation - Abstract
State of the art of optical coherent spectroscopy of doped solids that are promising as information carriers for optical processors is reviewed. Special attention is paid to optical echo spectroscopy of doped crystals classified as the Van-Vleck paramagnets where the long-lived stimulated echo is observed with the optical-memory time reaching several hours at low temperatures. Modern elaborations of optical echo processors based on this echo phenomenon are discussed. Physical principles of femtosecond echo spectroscopy and coherent four-wave mixing spectroscopy are formulated. The abilities of these methods in the diagnostics of fast processes at room temperature are illustrated using examples of a doped polymer films. The results of elaborations of a new branch of optical spectroscopy (biphoton spectroscopy) are also presented. The advantages and possible applications of this method are demonstrated using an example of two crystals (Er3+:YAG and Cr3+:Al2O3).
- Published
- 2010
32. Stimulated photon echo with temporal data coding in the Hopfield-Little regime
- Author
-
A. A. Kalachev, V. E. Vorobieva, and Vitaly V. Samartsev
- Subjects
Physics ,Photon ,Physics::Optics ,General Physics and Astronomy ,Optical neural network ,Content-addressable memory ,Algorithm ,Associative property ,Temporal database ,Coding (social sciences) - Abstract
A model of an optical neural network with associative memory using stimulated photon echo (SPE) with temporal data coding is presented. The electrical field’s calculation of the SPE signals is carried out for case of multiple influences on the resonant medium by optical pulses. A computer model of an optical echo processor with associative retrieval of information is elaborated.
- Published
- 2009
33. Generation of narrow-band correlated photon pairs by spontaneous down conversion in a cavity
- Author
-
A. A. Kalinkin, A. A. Kalachev, A. V. Shkalikov, I. Z. Latypov, and Vitaly V. Samartsev
- Subjects
Physics ,Photon ,Field (physics) ,business.industry ,Wave packet ,Physics::Optics ,General Physics and Astronomy ,Resonance ,Nanosecond ,Optics ,Spontaneous parametric down-conversion ,Correlation function ,Nonlinear medium ,Physics::Chemical Physics ,Atomic physics ,business - Abstract
The problem of generating a narrow-band biphoton field during spontaneous parametric down conversion of light in a quadratic nonlinear medium in a cavity is discussed. It is shown that, in the case of double resonance (for signal and idle fields), the form of the single-photon wave packet is biexponential and has a half-width determined by the photon life time in the cavity. An experiment is carried out on the generation of narrow-band biphotons in a crystal of lithium iodine with I-type matching in a frequency degenerate collinear regime. The second-order correlation function of the cavity-enhanced biphotons is measured using the electric nanosecond time delay line.
- Published
- 2009
34. Formation of photonic echo signals in the presents of a strong concentration quenching effect
- Author
-
Alexey Tiranov, Vitaly V. Samartsev, A. A. Kalachev, V. A. Zuikov, and K. R. Karimullin
- Subjects
Materials science ,business.industry ,Echo (computing) ,Doping ,Physics::Optics ,General Physics and Astronomy ,chemistry.chemical_element ,Condensed Matter::Materials Science ,chemistry.chemical_compound ,Thulium ,Nuclear magnetic resonance ,chemistry ,Impurity ,Condensed Matter::Superconductivity ,Lanthanum trifluoride ,Optoelectronics ,Concentration quenching ,Photonics ,Spectroscopy ,business - Abstract
The connection between the photonic echo formation in crystals doped by rare-earth elements and the concentration effects was studied. The application of optical echo spectroscopy in studies of garnet crystals with a high content of thulium impurity was demonstrated. By the example of activated crystals of ruby and lanthanum trifluoride, the spectral transformation of the photonic echo signals was analyzed in the present of the concentration quenching effect.
- Published
- 2009
35. Femtosecond echo-processing in a dye-doped polymer film at room temperature
- Author
-
G. M. Safiullin, Vladimir S. Lobkov, A. V. Leontiev, Vitaly V. Samartsev, and Victor G. Nikiforov
- Subjects
chemistry.chemical_classification ,Materials science ,Physics and Astronomy (miscellaneous) ,business.industry ,Doping ,Nonlinear optics ,Polymer ,Laser ,law.invention ,Optics ,chemistry ,law ,Femtosecond ,business ,Homogeneous broadening ,Instrumentation ,Excitation ,Line (formation) - Abstract
The possibility to mechanize at room temperature a logical function of bit-to-bit parallel multiplication for optical echo-processor based on the third-order nonlinear optical response of a resonant medium is experimentally studied. The polyvinilbutural film doped with phthalocyanine dye was used as an operating medium in our experiments. The time needed to realize the logical operation, the result of which is presented in the spectrum of the nonlinear optical response of the medium after action of the two spectrally coded pumping pulses, is less than 1 ps. The values of a homogeneous broadening of S0 – S1 line Γhom = 89 cm-1 and Γhom = 44 cm-1 are established at T = 300 K and T = 77 K respectively. The laser excitation parameters needed for effective operating of optical processor are defined. The maximum word length achievable under current experimental conditions is estimated.
- Published
- 2009
36. Advances of laser refrigeration in solids
- Author
-
S. V. Petrushkin and Vitaly V. Samartsev
- Subjects
Materials science ,business.industry ,Physics::Optics ,Refrigeration ,Laser science ,Condensed Matter Physics ,Laser ,Industrial and Manufacturing Engineering ,Atomic and Molecular Physics, and Optics ,Nanocrystalline material ,law.invention ,Condensed Matter::Materials Science ,Raman cooling ,law ,Condensed Matter::Superconductivity ,Laser cooling ,Femtosecond ,Optoelectronics ,Condensed Matter::Strongly Correlated Electrons ,Physics::Atomic Physics ,Photonics ,business ,Instrumentation - Abstract
The physics of laser cooling in solids is discussed. The coherent optical cooling of dye-doped polymer films in regime of anti-Stokes femtosecond photon echo is analyzed. The possibility of improved optical cooling by doped nanocrystalline structures is studied.
- Published
- 2009
37. Optical echo-spectroscopy of highly doped Tm:YAG
- Author
-
Vitaly V. Samartsev, V. A. Zuikov, Alexey Kalachev, and K. R. Karimullin
- Subjects
Photon ,Materials science ,Physics and Astronomy (miscellaneous) ,Doping ,Relaxation (NMR) ,Phase (waves) ,Physics::Optics ,Magnetic field ,Intensity (physics) ,Crystal ,Nuclear magnetic resonance ,Atomic physics ,Spectroscopy ,Instrumentation - Abstract
Two-pulse, stimulated and accumulated photon echoes are investigated for the first time in a highly doped crystal Tm:YAG containing 10 at.% Tm3+. The decay curves of the two-pulse and stimulated photon echoes generated at 793.15 nm on the transition 3H6(1)–3H4(1) of the impurity ions are measured in the absence of an applied magnetic field and parameters describing the energy and phase relaxation are determined. The dependence of the intensity of the accumulated photon echo on the number of excitation pulse pairs is investigated.
- Published
- 2008
38. Photon echo in ruby doped only by53Cr isotope ions
- Author
-
T. G. Mitrofanova, Vitaly V. Samartsev, A. V. Shkalikov, and A. M. Shegeda
- Subjects
Wavelength ,Materials science ,Photon ,Physics and Astronomy (miscellaneous) ,Isotope ,Excited state ,Nanosecond ,Atomic physics ,Instrumentation ,Hyperfine structure ,Magnetic field ,Ion - Abstract
The signals of photon echo (PE) are investigated firstly in a ruby crystal doped only by the 53Cr isotope ions in a concentration of 0.03 – 0,05 wt%. The optical experiments were performed in backward regime at the wavelength of 693.4 nm both with a low magnetic field (200 G) and without it. Since the 53Cr isotope ions have hyperfine structure of levels the special attention was paid to the study of the stimulated photon echo and primarily to the investigation of its decay kinetics. It is established that this decay has a form which is typical to the signals of long-lived PE. But in contrast to the long-lived PE the decay time in our case is less than the lifetime of the excited 2E(Ē) state. The signals of primary photon echo and stimulated photon echo at a low longitudinal magnetic field and their decay curves are investigated. We observed the beats of temporal shape of these signals with a period of several tens of nanoseconds. Theoretical analysis shows that they are due to the hyperfine interaction of valence electrons of 53Cr isotope ions with their own nuclei. The obtained decay curves allow us to estimate the phase relaxation time at the presence of a magnetic field. It proves to be equal to 98 ns. The spectrum of stimulated photon echo signal in the doped ruby exposed to a magnetic field is measured.
- Published
- 2008
39. Biphoton spectroscopy of YAG:Er3+ crystal
- Author
-
A. A. Kalinkin, D A Kalashnikov, Alexey Kalachev, T. G. Mitrofanova, A. V. Shkalikov, and Vitaly V. Samartsev
- Subjects
Physics ,Photon ,Physics and Astronomy (miscellaneous) ,Absorption spectroscopy ,business.industry ,Physics::Optics ,law.invention ,Crystal ,Wavelength ,Optics ,Spontaneous parametric down-conversion ,law ,Thermal radiation ,business ,Spectroscopy ,Instrumentation ,Monochromator - Abstract
The absorption spectrum of Er3+ ions in YAG crystal in the range from 645 nm to 655 nm was measured with the resolution of 0.01 nm using the frequency-anticorrelated broadband photon pairs (biphotons) generated by spontaneous parametric down-conversion. The spectrum of the sample was measured by counting the coincidences when the impurity crystal was placed in front of the signal photon detector, whilst the wavelength of the idler photons was resolved by a monochromator which was placed in front of another photon detector. The results are in agreement with those obtained by the usual intensity measurements with a classical light source and a monochromator. It was shown experimentally that the biphoton spectroscopy, unlike the usual single photon spectroscopy, allows one to obtain the spectroscopic information in the presence of an external noise such as background thermal radiation.
- Published
- 2007
40. Cooperative superfluorescence in nanoclusters
- Author
-
Alexander V. Kir'yanov, Alexey Kalachev, T. G. Mitrofanova, and Vitaly V. Samartsev
- Subjects
Quantum optics ,Ytterbium ,Range (particle radiation) ,Optical fiber ,Materials science ,business.industry ,chemistry.chemical_element ,Condensed Matter Physics ,Laser ,Molecular physics ,Industrial and Manufacturing Engineering ,Atomic and Molecular Physics, and Optics ,law.invention ,Nanoclusters ,Optics ,chemistry ,law ,Photonics ,Luminescence ,business ,Instrumentation - Abstract
The features of superfluorescence (SF) in nanoclusters, which consist of a few neighboring particles interacting with each other by exchange or/and electrostatic forces, are investigated theoretically. It is shown that there are two types of cooperatively SF depending on the ratio between the linear size of a nanocluster and the cooperative interaction range. Experiments on cooperative luminescence in Ytterbium-doped silica fibers are analyzed. It is shown that the intensity of cooperative SF in such a system should be proportional to the fourth degree of Ytterbium concentration.
- Published
- 2007
41. Femtosecond photon echo in a dye-doped polymer film and the possibility of coherent optical cooling
- Author
-
S. V. Petrushkin, Vladimir S. Lobkov, A. Yu. Vorobyev, Vitaly V. Samartsev, Kev M. Salikhov, and G. M. Safiullin
- Subjects
chemistry.chemical_classification ,Femtosecond pulse shaping ,Materials science ,Photon ,business.industry ,Physics::Optics ,Polymer ,Condensed Matter Physics ,Industrial and Manufacturing Engineering ,Atomic and Molecular Physics, and Optics ,Spectral line ,Optics ,chemistry ,Impurity ,Laser cooling ,Femtosecond ,Molecule ,Atomic physics ,business ,Instrumentation - Abstract
The signals of primary and stimulated femtosecond photon echoes are investigated in a dye-doped polymer film at room temperature. The homogeneous So → S 1 spectral line width, which is due to the interaction between the impurity molecules and the quasi-local low-frequency modes, is estimated (≈5 x 10 12 Hz). Special attention is paid to the study of spectra of femtosecond echo signals. The short-wave shifts of these spectra, with respect to the spectrum of femtosecond exciting pulses, are observed. These shifts indicate that the anti-Stokes regime of femtosecond pulse emission is realized. Therefore, the coherent regime of laser cooling of solids appears to be possible. The prospects of using of this new cooling regime in the function of a solid-state optical refrigerator are discussed.
- Published
- 2007
42. Incoherent backward photon echo in ruby upon excitation through an optical fiber
- Author
-
K. R. Karimullin, T. G. Mitrofanova, A. M. Shegeda, V. A. Zuikov, A. V. Shkalikov, and Vitaly V. Samartsev
- Subjects
Excitation wavelength ,Optical fiber ,Materials science ,Photon ,Physics and Astronomy (miscellaneous) ,business.industry ,Decay curve ,Spectral line ,law.invention ,Optics ,law ,business ,Instrumentation ,Excitation ,Coherence (physics) - Abstract
The results of an experimental investigation of the incoherent photon echo in ruby (with Cr3+ concentration equal to 0.16 wt%) at T=1.7 K are presented. Optical fiber with length 3 m and diameter 100 μm was used for delivery of the first exciting pulse to a sample. The dependence of the IPE intensity on the excitation wavelength within the width of R1 absorption line was studied. The IPE decay curve was obtained and the phase relaxation time was found to be equal to 98 ns.
- Published
- 2007
43. Femtosecond primary and stimulated photon echoes in a dye-doped polymer film at room temperature
- Author
-
A. V. Leontiev, G. M. Safiullin, V. A. Zuikov, Kev M. Salikhov, A. Yu. Vorobyev, Vladimir S. Lobkov, and Vitaly V. Samartsev
- Subjects
Materials science ,Photon ,business.industry ,Physics::Medical Physics ,Echo (computing) ,Physics::Optics ,Condensed Matter Physics ,Laser ,Industrial and Manufacturing Engineering ,Atomic and Molecular Physics, and Optics ,Spectral line ,law.invention ,Optics ,law ,Excited state ,Laser cooling ,Femtosecond ,Atomic physics ,business ,Instrumentation ,Excitation - Abstract
The signals of both primary and stimulated femtosecond photon echoes are observed and investigated in a dye-doped polymer film at room temperature using a modernized femtosecond echo-spectrometer. It should be noted that stimulated photon echo in the solid-state sample is observed for the first time at such a high temperature. Experimentally obtained decay curves of these signals have a nonexponential character. The spectra of these echo signals are also measured. It is found that the spectrum of the primary photon echo is short-wave shifted with respect to the spectrum of excitation. This can be used for the coherent laser cooling of a sample. The spectrum of the stimulated photon echo is also shifted to the short-wave range relative to the spectrum of excitation, but its shift is much less than that of the primary photon echo. The experiment shows that the femtosecond echo signals at room temperature are excited via the phonon-side band of the absorption line.
- Published
- 2007
44. Low magnetic fields behavior of photon echo in LuLiF4:Er3+
- Author
-
V. A. Zuikov, V. N. Lisin, Stella L. Korableva, Vitaly V. Samartsev, and A. M. Shegeda
- Subjects
Physics ,Photon ,Physics and Astronomy (miscellaneous) ,Condensed matter physics ,business.industry ,Magnetic field magnitude ,Polarization (waves) ,Laser ,Exponential function ,Magnetic field ,law.invention ,Optics ,Exponential growth ,law ,Exponential decay ,business ,Instrumentation - Abstract
It is reported about the first observation and studying of the photon echo in LuLiF4:Er3+. The energy transition is 4I15/2→4F9/2 (λ=6536 Å). The density of ErF3 is 0.025 wt%. The operation temperature is 1.9 K. Measurements were spent at low (up to 1200 Oe) and even zero external magnetic fields. It was studied a behavior of the photon echo intensity versus the magnetic field magnitude and direction about the crystal axis C and versus the laser pulse separation t 12. It was observed an exponential growth and then, after some plateau, an exponential decreasing of the photon echo intensity as a function of magnetic field with increasing of the magnetic field from zero value. The parameters describing the exponential growth and decreasing are not depended on direction of magnetic field. Value of a magnetic field at which the echo intensity accepts the maximum, and quantity of this maximum decrease with increased the pulse separation t 12 and the angle θ between the magnetic field and crystal axis. The echo intensity exponentially decreases with increased θ. The parameter describing the exponential decreasing is not depended on the magnitude of the field. The echo intensity as a function of pulse separation shows exponential decay. The phase relaxation time is depended on the magnitude and direction of the magnetic field. T 2 is equal to 202±16 ns at zero magnetic field. Phenomenological formula is suggested, which qualitatively presents the mentioned dependencies. Polarization properties of the backward photon echo in this crystal are studied also.
- Published
- 2006
45. Quantum memory and quantum computations in the optical subradiance regime
- Author
-
Vitaly V. Samartsev and A A Kalachev
- Subjects
Physics ,Quantum optics ,Quantum network ,Quantum simulator ,Statistical and Nonlinear Physics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Quantum technology ,Open quantum system ,Quantum gate ,Quantum mechanics ,Qubit ,Electrical and Electronic Engineering ,Quantum computer - Abstract
The possibilities of creation and manipulation of subradiant states in an extended atomic system by coherent 2π pulses are analysed. It is shown that excitation of the atomic system to collective subradiant states eliminates the superradiant broadening of the resonance line in quantum optical memory devices. The scheme of a nonlinear sign-shift two-qubit gate is proposed, which can be used in optical quantum computers.
- Published
- 2005
46. Femtosecond photon echo in dye-doped polymer film at room temperature
- Author
-
V. A. Zuikov, Kev M. Salikhov, G. M. Safiullin, Vladimir S. Lobkov, and Vitaly V. Samartsev
- Subjects
education.field_of_study ,Materials science ,Photon ,Physics and Astronomy (miscellaneous) ,business.industry ,Population ,Relaxation (NMR) ,Physics::Optics ,Liquid nitrogen ,Grating ,Laser ,law.invention ,Wavelength ,Optics ,law ,Femtosecond ,Optoelectronics ,education ,business ,Instrumentation - Abstract
The first observation is reported of the primary and stimulated femtosecond photon echoes at liquid nitrogen and room temperatures in a dye-doped polymer film at a wavelength of 780 nm. Echo signals were generated by pulses with the duration of 65 fs. The primary echo signal decay at liquid nitrogen and room temperatures can not be described by a simple exponential function. The decay of primary echo signal at room temperature demonstrates complex behavior caused by the presence of the phonon-side band in the optical band of impurity centers. There were also detected signals of the self-diffraction of exciting pulses on a nonequilibrium population difference grating, induced in resonant medium by these pulses.
- Published
- 2005
47. Multipulse regimes of excitation of optical superradiance due to a two-photon transition
- Author
-
A. A. Kalinkin, A. A. Kalachev, and Vitaly V. Samartsev
- Subjects
Physics ,Photon ,Multi-mode optical fiber ,business.industry ,Physics::Optics ,Superradiance ,Population inversion ,Laser ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,law ,Quantum mechanics ,Atomic physics ,Photonics ,business ,Excitation ,Coherence (physics) - Abstract
Multimode triggered optical superradiance due to a two-photon transition is theoretically studied. Kinetic equations are derived for the dynamics of cooperative development of coherence and population inversion of optical centers interacting with each other through a common field of emitted photons. Various regimes of triggering of optical superradiance due to a two-photon transition are considered. The possibility of creating a quantum photomultiplier on the basis of the triggered optical superradiance is discussed.
- Published
- 2004
48. Optical two-colour superfluorescence in biphenyl crystal with pyrene: the influence of crystal symmetry
- Author
-
N. B. Silaeva, P. V. Zinoviev, A. A. Kalinkin, A. A. Kalachev, and Vitaly V. Samartsev
- Subjects
Biphenyl ,Materials science ,Physics and Astronomy (miscellaneous) ,media_common.quotation_subject ,Physics::Optics ,Superradiance ,Crystal structure ,Polarization (waves) ,Molecular physics ,Asymmetry ,chemistry.chemical_compound ,chemistry ,Pyrene ,Molecule ,Emission spectrum ,Instrumentation ,media_common - Abstract
The influence of crystal symmetry on the polarization properties of two-colour optical superfluorescence in biphenyl crystal with pyrene is investigated both theoretically and experimentally. It is shown that polarization of superfluorescence signal is determined by the asymmetry between absorbtion and emission spectra of pyrene molecules in biphenyl, which results in polarization decoupling of pumping and superfluorescence pulses.
- Published
- 2004
49. Amplification of squeezed light in the regime of triggered optical superradiance
- Author
-
A A Kalachev and Vitaly V. Samartsev
- Subjects
Condensed Matter::Quantum Gases ,Physics ,Vacuum state ,Statistical and Nonlinear Physics ,Superradiance ,Quantum Physics ,Population inversion ,Polarization (waves) ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Quantum electrodynamics ,Quantum mechanics ,Stimulated emission ,Electrical and Electronic Engineering ,Dispersion (chemistry) ,Quantum ,Squeezed coherent state - Abstract
The possibility of amplification of pulses of squeezed light in the regime of triggered optical superradiance is analysed. The kinetic equations are obtained which describe the dynamics of cooperative development of the population inversion and dispersion of the quadrature components of polarisation of optical centres interacting with the triggering-pulse field in the squeezed vacuum state. The dependence of the squeezing degree of the superradiance field on the squeezing degrees of the triggering-pulse field and polarisation of an amplifying medium is determined. It is shown that in the case of a sufficiently strong squeezing of the medium, the intensity of the squeezed quadrature component of the superradiance signal is lower than that of an incoherent spontaneous background. Therefore, the superradiance field can be characterised not only by a classical squeezing (when the dispersions of quadratures are not identical) but also by a quantum squeezing (when the dispersion of one quadrature is smaller than its vacuum value).
- Published
- 2002
50. Optical memory based on the long-lived photon echo and optical superradiance in crystals doped by rare-earth ions
- Author
-
Vitaly V. Samartsev and A. A. Kalachev
- Subjects
Quantum optics ,Photon ,business.industry ,Chemistry ,Echo (computing) ,Doping ,Biophysics ,Superradiance ,General Chemistry ,Condensed Matter Physics ,Biochemistry ,Atomic and Molecular Physics, and Optics ,Crystal ,Optics ,Optical memory ,Rare earth ions ,Atomic physics ,business - Abstract
The problems of optical memory (OM) based on the long-lived stimulated photon echo and multichannel optical superradiance are discussed. Experiments on the observation of optical superradiance in LaF 3 :Pr 3+ crystal and triggering superradiance in biphenyl crystal doped by pyrene have been described. The possible architecture of the storage unit based on the multichannel optical superradiance is present.
- Published
- 2002
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.