The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
C D Lin - One of the best experts on this subject based on the ideXlab platform.
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absorption and emission of single attosecond light pulses in an autoionizing Gaseous Medium dressed by a time delayed control field
Physical Review A, 2013Co-Authors: Weichun Chu, C D LinAbstract:by the coupling laser. A simple analytical expression for the atomic response derived for δ-function pulses reveals the strong modification of the Fano lineshape in the spectra, where these features are quite universal and remain valid for realistic pulse conditions. We further account for the propagation of pulses in the Medium and show that the EUV signal at the atomic resonance can be enhanced in the Gaseous Medium by more than 50% for specifically adjusted laser parameters, and that this enhancement persists as the EUV propagates in the Gaseous Medium. Our result demonstrates the high-level control of nonlinear optical effects that are achievable with attosecond pulses.
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Absorption and emission of single attosecond light pulses in an autoionizing Gaseous Medium dressed by a time-delayed control field
Physical Review A, 2013Co-Authors: Weichun Chu, C D LinAbstract:An extreme ultraviolet (EUV) single attosecond pulse passing through a laser-dressed dense gas is studied theoretically. The weak EUV pulse pumps the helium gas from the ground state to the $2s2p({}^{1}P)$ autoionizing state, which is coupled to the $2{s}^{2}{(}^{1}S)$ autoionizing state by a femtosecond infrared laser with the intensity in the order of 10${}^{12}$ W/cm${}^{2}$. The simulation shows how the transient absorption and emission of the EUV are modified by the coupling laser. A simple analytical expression for the atomic response derived for $\ensuremath{\delta}$-function pulses reveals the strong modification of the Fano lineshape in the spectra, where these features are quite universal and remain valid for realistic pulse conditions. We further account for the propagation of pulses in the Medium and show that the EUV signal at the atomic resonance can be enhanced in the Gaseous Medium by more than 50$%$ for specifically adjusted laser parameters, and that this enhancement persists as the EUV propagates in the Gaseous Medium. Our result demonstrates the high-level control of nonlinear optical effects that are achievable with attosecond pulses.
Weichun Chu - One of the best experts on this subject based on the ideXlab platform.
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absorption and emission of single attosecond light pulses in an autoionizing Gaseous Medium dressed by a time delayed control field
Physical Review A, 2013Co-Authors: Weichun Chu, C D LinAbstract:by the coupling laser. A simple analytical expression for the atomic response derived for δ-function pulses reveals the strong modification of the Fano lineshape in the spectra, where these features are quite universal and remain valid for realistic pulse conditions. We further account for the propagation of pulses in the Medium and show that the EUV signal at the atomic resonance can be enhanced in the Gaseous Medium by more than 50% for specifically adjusted laser parameters, and that this enhancement persists as the EUV propagates in the Gaseous Medium. Our result demonstrates the high-level control of nonlinear optical effects that are achievable with attosecond pulses.
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Absorption and emission of single attosecond light pulses in an autoionizing Gaseous Medium dressed by a time-delayed control field
Physical Review A, 2013Co-Authors: Weichun Chu, C D LinAbstract:An extreme ultraviolet (EUV) single attosecond pulse passing through a laser-dressed dense gas is studied theoretically. The weak EUV pulse pumps the helium gas from the ground state to the $2s2p({}^{1}P)$ autoionizing state, which is coupled to the $2{s}^{2}{(}^{1}S)$ autoionizing state by a femtosecond infrared laser with the intensity in the order of 10${}^{12}$ W/cm${}^{2}$. The simulation shows how the transient absorption and emission of the EUV are modified by the coupling laser. A simple analytical expression for the atomic response derived for $\ensuremath{\delta}$-function pulses reveals the strong modification of the Fano lineshape in the spectra, where these features are quite universal and remain valid for realistic pulse conditions. We further account for the propagation of pulses in the Medium and show that the EUV signal at the atomic resonance can be enhanced in the Gaseous Medium by more than 50$%$ for specifically adjusted laser parameters, and that this enhancement persists as the EUV propagates in the Gaseous Medium. Our result demonstrates the high-level control of nonlinear optical effects that are achievable with attosecond pulses.
Nikita A. Toropov - One of the best experts on this subject based on the ideXlab platform.
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Enhancement of Raman scattering of a Gaseous Medium near the surface of a silver holographic grating.
Optics letters, 2017Co-Authors: Dmitry Petrov, A. R. Zaripov, Nikita A. ToropovAbstract:The Letter demonstrates a possibility to enhance the Raman scattering of a Gaseous Medium due to an enhanced electromagnetic field caused by the excitation of propagating surface plasmon polaritons (PSPPs) on a silver holographic grating. Efficiency of collinear and noncollinear schemes of PSPP excitation on a metal–Gaseous Medium interface was studied. When using a collinear scheme, we registered an eightfold enhancement of the Raman scattering of atmospheric nitrogen and oxygen, where the average gain near the PSPP-active surface was ∼4×103.
N. V. Malai - One of the best experts on this subject based on the ideXlab platform.
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Investigation of boundary-value problem for slow flow of a sphere by viscous non-isothermal gas
Russian Mathematics, 2016Co-Authors: N. V. Malai, A V Glushak, A. V. LimanskayaAbstract:We obtain a solution to a boundary-value problem of a flow of spherical form particle for stationary system of equations of viscous non-isothermal Gaseous Medium including the Stokes equation, heat conductivity equation, and state equation with account taken of dependence of viscosity, heat conductivity, and density of Gaseous Medium on temperature.
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Photophoresis of heated moderately large spherical aerosol particles
Atmospheric and Oceanic Optics, 2012Co-Authors: N. V. Malai, E. R. Shchukin, A. V. Limanskaya, A. A. StukalovAbstract:Steady-state motion of a moderately large solid aerosol spherical particle electromagnetically irradiated in a gas is described theoretically in the Stokes approximation. In the consideration of the motion, it was supposed that the average temperature of the particle surface could differ considerably from the temperature of the Gaseous Medium surrounding the particle. In the process of the solution of the gas dynamic equations, analytical expressions for the photophoresis force and velocity were obtained, with allowance for the dependencies of density and viscosity of the Gaseous Medium and thermal conductivity on temperature.
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On the gravitational motion of a nonuniformly heated solid particle in a Gaseous Medium
Technical Physics, 2010Co-Authors: N. V. Malai, A. A. Stukalov, E. R. Shchukin, K. S. RyazanovAbstract:The steady motion of a nonuniformly heated spherical aerosol particle through a viscous Gaseous Medium is theoretically studied in the Stokes approximation. It is assumed that the mean temperature of the particle surface may differ appreciably from the ambient temperature. The solution of gasdynamic equations yields an analytical expression for the drag of the Medium and the gravitational fall velocity of the nonuniformly heated spherical solid particle with allowance for the temperature dependence of the density of the Medium and molecular transfer coefficients (viscosity and thermal conductivity). Numerical estimates show that heating of the particle surface considerably influences the drag force and gravitational fall velocity.
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Gravity-induced motion of a uniformly heated solid particle in a Gaseous Medium
Journal of Applied Mechanics and Technical Physics, 2008Co-Authors: N. V. Malai, A. A. Stukalov, E. R. Shchukin, K. S. RyazanovAbstract:The steady motion of a uniformly heated spherical aerosol particle in a viscous Gaseous Medium is analyzed in the Stokes approximation under the condition that the mean temperature of the particle surface can be substantially different from the ambient temperature. An analytical expression for the drag force and the velocity of gravity-induced motion of the uniformly heated spherical solid particle is derived with allowance for temperature dependences of the Gaseous Medium density, viscosity, and thermal conductivity. It is numerically demonstrated that heating of the particle surface has a significant effect on the drag and velocity of gravity-induced motion.
Dmitry Petrov - One of the best experts on this subject based on the ideXlab platform.
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Enhancement of Raman scattering of a Gaseous Medium near the surface of a silver holographic grating.
Optics letters, 2017Co-Authors: Dmitry Petrov, A. R. Zaripov, Nikita A. ToropovAbstract:The Letter demonstrates a possibility to enhance the Raman scattering of a Gaseous Medium due to an enhanced electromagnetic field caused by the excitation of propagating surface plasmon polaritons (PSPPs) on a silver holographic grating. Efficiency of collinear and noncollinear schemes of PSPP excitation on a metal–Gaseous Medium interface was studied. When using a collinear scheme, we registered an eightfold enhancement of the Raman scattering of atmospheric nitrogen and oxygen, where the average gain near the PSPP-active surface was ∼4×103.
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Enhancement of Raman scattering signals from Gaseous Medium near the surface of a holographic aluminum diffraction grating
Technical Physics Letters, 2016Co-Authors: Dmitry Petrov, Danila O. Sedinkin, A. R. ZaripovAbstract:The possibility of applying surface-enhanced Raman scattering (RS) for amplification of RS intensity in Gaseous media is investigated. A more than sixfold enhancement of the RS signal is detected experimentally from the main atmospheric air components during interaction of continuous-wave laser radiation with a holographic aluminum diffraction grating. The averaged value of the RS signals’ amplification factor in the near-surface 30-nm-thick layer at the boundary between the diffraction grating and Gaseous Medium amounted to ~3 × 103.
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Investigation of a possibility of enhancement of Raman signals from Gaseous Medium due to plasmon resonance on the Al-grating
22nd International Symposium on Atmospheric and Ocean Optics: Atmospheric Physics, 2016Co-Authors: Dmitry Petrov, Danila O. Sedinkin, A. R. ZaripovAbstract:A possibility of applying SERS effect to enhance the intensity of the Raman spectra of Gaseous media is investigated. More than 6-fold increase in Raman signals of the main components of air has been experimentally recorded due to increasing the electromagnetic field near an aluminum holographic diffraction grating. The average gain of Raman signals in the 30-nm layer at the grating – Gaseous Medium boundary was ~ 3×10 3 .