Showing papers by "Andrey Popov published in 2000"
TL;DR: In this article, a rigid polymer recording medium with self-amplification of holograms owing to diffusion of phenanthrenequinone molecules was used to find efficient holographic optical elements with high-spectral-selectivity interference filters and multiple demultiplexers.
Abstract: A thick rigid polymer recording medium with self-amplification of holograms owing to diffusion of phenanthrenequinone molecules was used to find efficient holographic optical elements with high-spectral-selectivity interference filters and multiple demultiplexers. Several examples of practical applications are briefly described in this paper, showing the benefits of such optical elements for the fields of astronomy, spectroscopy and communication technologies.
30 citations
TL;DR: In this paper, an alternate solution to the problem of adequately describing the evolution of optical spectra of any polydisperse silver colloids with particles falling within a range of most characteristic sizes (5 − 30 nm), over which the results of the application of the methods of classical electrodynamics including the Mie theory, disagree with experimental data, was proposed.
Abstract: Based on the theory of the optical properties of fractal clusters, an alternate solution to the problem of adequately describing the evolution of optical spectra of any polydisperse silver colloids with particles falling within a range of most characteristic sizes (5–30 nm), over which the results of the application of the methods of classical electrodynamics including the Mie theory, disagree with experimental data, was proposed. The effect of various parameters of such media on optical spectra was studied by a mathematical simulation with allowance for particle electrodynamic interaction. An obvious quantitative explanation is given for the reasons for the appearance of individual specific features in contours of the spectral absorption of different-type silver colloids.
18 citations
TL;DR: In this paper, atoms from a wide velocity interval can be concurrently involved in Doppler-free two-photon resonant four-wave mixing that is far from being frequency dependent, with the aid of an auxiliary electromagnetic field.
Abstract: We show that atoms from a wide velocity interval can be concurrently involved in Doppler-free two-photon resonant four-wave mixing that is far from being frequency dependent, with the aid of an auxiliary electromagnetic field. This gives rise to substantial enhancement of the output radiation generated in an optically thick medium. Numerical illustrations of typical experimental conditions are given.
15 citations
TL;DR: In this article, the authors proposed a four-level model where sub-Doppler resolution as well as enhanced absorption of a weak probe field are realized by using two coherently driving fields.
Abstract: We propose a four-level model where sub-Doppler resolution as well as enhanced absorption of a weak probe field are realized by using two coherently driving fields. We show that spectral resolution can be improved by modifying the coherent fields intensity and frequencies.
9 citations
TL;DR: In this paper, a correction in terms of the integral characteristics of this deviation is obtained and it is valid ifa sin δ<λ, wherea is the depth of the contaminated layer, and λ and δ are the wavelength and grazing angle of the incident beam, respectively.
Abstract: The spatial profile of the dielectric pemittivity of any bulk sample is always to some extent smoothed or modified by various factors including interaction with atmospheric and environmental gases. This fact hinders optical measurements and should be taken into account in the interpretation of experimental data. The modification of the Fresnel reflectivity formula for the case where the spatial permittivity distribution deviates from an abrupt stepwise profile is considered. A correction in terms of the integral characteristics of this deviation is obtained and it is valid ifa sin δ<λ, wherea is the depth of the contaminated layer, and λ and δ are the wavelength and grazing angle of the incident beam, respectively.
9 citations
TL;DR: In this paper, a degenerate three-level system driven by a strong external field and by collisions with a buffer gas is investigated, and the mechanism of population distribution in upper laser level, contributed by the collision transfer, as well as by relaxation induced by pressure of buffer gas, is discussed in detail.
Abstract: Inversionless gain in a degenerate three-level system driven by a strong external field and by collisions with a buffer gas is investigated. The mechanism of population distribution in upper laser level, contributed by the collision transfer, as well as by relaxation, induced by pressure of a buffer gas, is discussed in detail. Explicit formulae for analysis of optimal conditions are derived. The idea developed here for the incoherent pump could be generalized to other systems.
5 citations
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TL;DR: In this article, the effect of a strong field on the shape of the amplification spectral line for mono-velocity V-type three-level atoms was analyzed and the conditions under which each of the contributions is predominant.
Abstract: An analysis is made of the effect of a strong field on the shape of the amplification spectral line for mono-velocity V-type three-level atoms. There are three strong-field contributions, differing in their dependence on the set of relaxation parameters of the medium and on the differences among the populations corresponding to the Raman transitions. An analysis is made of the conditions under which each of the contributions is predominant. The change in the line shape by an intensified external field is found for each case. Neon atoms are discussed as an example. The results are compared with those corresponding to a Maxwellian velocity distribution.
5 citations
TL;DR: Virtual experiments aimed at inversionless short-wavelength amplification and numerical simulations related to the proposed experiment in optically-dense sodium dimer vapor show optimal condition for optical switching and the expected gain of the probe radiation, above the oscillation threshold.
Abstract: Resonant nonlinear-optical interference processes in four-level Doppler-broadened media are studied. Specific features of amplification and optical switching of short-wavelength radiation in a strongly-absorbing resonant gas under coherent quantum control with two longer wavelength radiations, are investigated. The major outcomes are illustrated with virtual experiments aimed at inversionless short-wavelength amplification, which also address deficiencies in this regard in recent experiments. With numerical simulations related to the proposed experiment in optically-dense sodium dimer vapor, we show optimal condition for optical switching and the expected gain of the probe radiation, which is above the oscillation threshold.
5 citations
TL;DR: An inversionless gain of anti-Stokes radiation above the oscillation threshold in an optically dense far-from-degenerate double- ?
Abstract: An inversionless gain of anti-Stokes radiation above the oscillation threshold in an optically dense far-from-degenerate double-Λ Doppler-broadened medium accompanied by Stokes gain is predicted The outcomes are illustrated with numerical simulations applied to sodium dimer vapor Optical switching from absorption to gain via transparency controlled by a small variation of the medium and of the driving radiation parameters, which are at a level of less than one photon per molecule, is shown
5 citations
TL;DR: In this paper, the feasibility of coherent quantum control of four-wave mixing processes in a resonant Doppler-broadened medium is studied. And the major outcomes of the analysis are illustrated with numerical simulation addressed within a practical medium.
Abstract: New feasibity of coherent quantum control of four-wave mixing processes in a resonant Doppler-broadened medium are studied. We propose a technique which enables one to enhance the quantum efficiency of nonlinear optical conversion. At the same time, it allows one to decrease the required intensities of the fundamental beams compared to those necessary in the approach based on coherent population trapping. The major outcomes of the analysis are illustrated with numerical simulation addressed within a practical medium.
4 citations
TL;DR: In this article, specific features of amplification and optical switching of short-wavelength radiation in a strongly absorbing resonant gas under coherent quantum control with two longer wavelength radiations are investigated.
Abstract: Resonant nonlinear-optical interference processes in four-level Doppler-broadened media are studied. Specific features of amplification and optical switching of short-wavelength radiation in a strongly-absorbing resonant gas under coherent quantum control with two longer wavelength radiations, are investigated. The major outcomes are illustrated with virtual experiments aimed at inversionless short-wavelength amplification, which also address deficiencies in this regard in recent experiments. With numerical simulations related to the proposed experiment in optically-dense sodium dimer vapor, we show optimal condition for optical switching and the expected gain of the probe radiation, which is above the oscillation threshold.
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TL;DR: In this paper, the effects of coherence of quantum transitions and the interference of resonant nonlinear optical processes on the spectra of absorption, amplification, and nonlinear-optical generation are considered.
Abstract: The effects of coherence of quantum transitions and the interference of resonant nonlinear optical processes on the spectra of absorption, amplification, and nonlinear-optical generation are considered. The most favorable conditions are discussed for the inversionless amplification, resonant refraction in the absence of absorption and for resonant enhancement of nonlinear-optical generation at the discrete transitions and the transitions to continuum.