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Title: Peculiarities of the fundamental mode structure in stable-resonator lasers upon spatially inhomogeneous amplification

Abstract

The structure of the fundamental mode of a laser is calculated by the iteration Fox-Li method in the case of inhomogeneous unsaturated amplification produced by axially symmetric longitudinal pumping. The calculation is performed for different parameters g{sub 1} and g{sub 2} of the resonator within the entire stability region. It is shown that in the case of inhomogeneous amplification, the fundamental mode considerably deviates from the Gaussian mode of an empty resonator only in the so-called critical configurations of the resonator, when the quantity [arccos(g{sub 1}g{sub 2}){sup 1/2}]/{pi} is zero or takes a number of values expressed by irreducible fractions m/n. For the Fresnel number N{sub F} = 9, configurations with m/n = 1/2, 2/5, 3/8, 1/3, 3/10, 1/4, 1/5, 1/6, 1/8, and 1/10 are pronounced. As N{sub F} increases, the number of critical configurations increases. The expansion in a system of Laguerre-Gaussian beams shows that the fundamental mode in critical configurations is formed by a set of beams with certain radial indices p phased in the active medium. (resonators. modes)

Authors:
 [1]; ; ; ;  [2]
  1. P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)
  2. M. V. Lomonosov Moscow State University, Faculty of Physics, Moscow (Russian Federation)
Publication Date:
OSTI Identifier:
21466619
Resource Type:
Journal Article
Resource Relation:
Journal Name: Quantum Electronics (Woodbury, N.Y.); Journal Volume: 37; Journal Issue: 2; Other Information: DOI: 10.1070/QE2007v037n02ABEH013274
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AMPLIFICATION; AXIAL SYMMETRY; BEAMS; CALCULATION METHODS; CONFIGURATION; LASERS; PUMPING; RESONATORS; ELECTRONIC EQUIPMENT; EQUIPMENT; SYMMETRY

Citation Formats

Gorbunkov, Mikhail V, Kostryukov, P V, Telegin, L S, Tunkin, V G, and Yakovlev, D V. Peculiarities of the fundamental mode structure in stable-resonator lasers upon spatially inhomogeneous amplification. United States: N. p., 2007. Web. doi:10.1070/QE2007V037N02ABEH013274.
Gorbunkov, Mikhail V, Kostryukov, P V, Telegin, L S, Tunkin, V G, & Yakovlev, D V. Peculiarities of the fundamental mode structure in stable-resonator lasers upon spatially inhomogeneous amplification. United States. doi:10.1070/QE2007V037N02ABEH013274.
Gorbunkov, Mikhail V, Kostryukov, P V, Telegin, L S, Tunkin, V G, and Yakovlev, D V. Wed . "Peculiarities of the fundamental mode structure in stable-resonator lasers upon spatially inhomogeneous amplification". United States. doi:10.1070/QE2007V037N02ABEH013274.
@article{osti_21466619,
title = {Peculiarities of the fundamental mode structure in stable-resonator lasers upon spatially inhomogeneous amplification},
author = {Gorbunkov, Mikhail V and Kostryukov, P V and Telegin, L S and Tunkin, V G and Yakovlev, D V},
abstractNote = {The structure of the fundamental mode of a laser is calculated by the iteration Fox-Li method in the case of inhomogeneous unsaturated amplification produced by axially symmetric longitudinal pumping. The calculation is performed for different parameters g{sub 1} and g{sub 2} of the resonator within the entire stability region. It is shown that in the case of inhomogeneous amplification, the fundamental mode considerably deviates from the Gaussian mode of an empty resonator only in the so-called critical configurations of the resonator, when the quantity [arccos(g{sub 1}g{sub 2}){sup 1/2}]/{pi} is zero or takes a number of values expressed by irreducible fractions m/n. For the Fresnel number N{sub F} = 9, configurations with m/n = 1/2, 2/5, 3/8, 1/3, 3/10, 1/4, 1/5, 1/6, 1/8, and 1/10 are pronounced. As N{sub F} increases, the number of critical configurations increases. The expansion in a system of Laguerre-Gaussian beams shows that the fundamental mode in critical configurations is formed by a set of beams with certain radial indices p phased in the active medium. (resonators. modes)},
doi = {10.1070/QE2007V037N02ABEH013274},
journal = {Quantum Electronics (Woodbury, N.Y.)},
number = 2,
volume = 37,
place = {United States},
year = {Wed Feb 28 00:00:00 EST 2007},
month = {Wed Feb 28 00:00:00 EST 2007}
}
  • The combined influence of the resonator parameters and spatially nonuniform axially symmetric amplification distribution in a four-level active medium on the spatial structure of the fundamental mode of laser radiation is studied numerically by the Fox-Li method. The model of two beams interacting due to the spatial amplification nonuniformity is used to obtain simple analytic estimates. The transition of the spatial structure of the fundamental mode from the Gaussian one to the structure formed by a set of Laguerre-Gaussian beams is studied. It is shown that near the degenerate configurations of the resonator a decrease in the diameter of themore » pump beam leads to an increase in the number of Laguerre-Gaussian beams forming the fundamental mode. It is found that the range of detunings from the strong degeneracy within which substantial differences of the spatial structure of the fundamental mode from the Gaussian structure are realised, increases with increasing the gain. (resonators. modes)« less
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  • A numerical investigation of the distribution of the radiation field in a plane-parallel Fabry-Perot resonator in single-mode operation in the case of a simple model of kinetics with consideration of collisional relaxation was carried out with the use of the self-consistent statement of the problem proposed in (1).
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