Wave-optics description of amplified spontaneous emission

Journal Article · Wed May 01 04:00:00 EDT 1991 · Physical Review, A; (USA)

DOI:https://doi.org/10.1103/PhysRevA.43.4941· OSTI ID:5728456

Garrison, J C; Ritchie, B; Nathel, H; Hong, C K; Minner, L ^[1]

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1. Lawrence Livermore National Laboratory, University of California, Livermore, California 94550 (US)

Paraxial Maxwell-Bloch theory is used to describe amplified spontaneous emission (ASE) in strongly inverted media. Counterpropagation of waves coupled through gain saturation and diffraction, and pumping by a laser beam which propagates transverse to the amplifier are included in the treatment. The reactive part of the medium polarization is calculated by population-rate equations in the limit of rapid dephasing of the atomic dipoles. The spontaneous emission noise source needed for the numerical simulation of Maxwell's equations is derived from microscopic theory by coarse-graining, thereby establishing the compatibility of the spherically symmetric microscopic source with paraxial propagation theory. The three coupled Maxwell equations for the counterpropagating ASE waves and the transversely propagating pump wave are solved numerically in time and two spatial dimensions. This simulation is used to calculate the longitudinal profile of the transverse fluorescence, which measures the saturation of the gain, the longitudinal profile of the transmitted pump wave, which measures the saturation of pump absorption, and the transverse coherence function of the radiation emitted from the ends of the amplifier.

• OSTI ID: 5728456
• Journal Information: Physical Review, A; (USA), Journal Name: Physical Review, A; (USA) Vol. 43:9; ISSN 1050-2947; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

657000* -- Theoretical & Mathematical Physics
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMPLIFICATION
ATOMS
BLOCH THEORY
DIFFERENTIAL EQUATIONS
ELECTROMAGNETIC RADIATION
EQUATIONS
FLUORESCENCE
LUMINESCENCE
MOLECULES
PARTIAL DIFFERENTIAL EQUATIONS
POPULATION INVERSION
RADIATIONS
TRANSITION RADIATION
WAVE EQUATIONS
WAVE PROPAGATION