Europhys. Lett.
Volume 65, Number 5, March 2004
Page(s) 658 - 664
Section Electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics
Published online 01 February 2004
Europhys. Lett., 65 (5) , pp. 658-664 (2004)
DOI: 10.1209/epl/i2003-10168-1

Holographic screening-photovoltaic solitons in biased photovoltaic-photorefractive crystals with two-wave mixing

Jinsong Liu1 and H. J. Eichler2

1  State Key Laboratory of Laser Technology Huazhong University of Science and Technology Wuhan, 430074, PRC
2  Optisches Institut, Technische Universitaet Berlin Strasse des 17 Juni, 135, D-10623 Berlin, Germany

(Received 18 September 2003; accepted 16 December 2003)

We propose a new kind of optical spatial solitons in biased photovoltaic-photorefractive materials when the self-trapping beam couples coherently with a pump beam by codirectional degenerate two-wave mixing. Such solitons are a result of double balance, i.e., loss is balanced by gain provided by the pump beam via two-wave mixing, and diffraction is balanced by nonlinearity that is due to the spatially nonuniform screening of the applied field, the photovoltaic effect, and the periodic modulation of the refractive index via two-wave mixing. These solitons possess some unique properties, are stable relative to small perturbations, and can become screening-photovoltaic solitons if the pump beam is switched to a background illumination.

42.65.Tg - Optical solitons; nonlinear guided waves.
42.65.Jx - Beam trapping, self-focusing and defocusing; self-phase modulation.
42.65.Hw - Phase conjugation; photorefractive and Kerr effects.

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