Berlin 2001 – scientific programme

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Q: Quantenoptik

Q 16: Nonlinear Optics II

Q 16.2: Talk

Tuesday, April 3, 2001, 17:45–18:00, H 2013

Observation of spatial (2+1)D vector solitons in a saturable nonlinear medium — •Marcus Ahles, Carsten Weilnau, and Cornelia Denz — Institut für Angewandte Physik, Technische Universität Darmstadt

Optical spatial solitons in (2+1) dimensions are self-trapped light beams that can form in a saturable Kerr-like nonlinear medium. A laser beam that propagates through a photorefractive SBN crystal induces a refractive index modulation, which under certain conditions compensates exactly the beam’s natural diffraction in both transverse directions. The light propagates as fundamental mode of its own self-induced waveguide. Higher-order Hermite-Gaussian or Laguerre-Gaussian transverse modes do not self-trap, due to their non-uniform transverse phase distribution. However, when they co-propagate with a mutual incoherent fundamental Gaussian beam of equal total power, a stationary self-trapped state will form which is denoted as a vector soliton. Our investigations concentrate on the generation of spatial vector solitons consisting of one fundamental Gaussian and one higher-order mode component as e.g. a HG₀₁, a HG₀₂ or a HG₁₁ transversal mode. We demonstrate the existence of these theoretically predicted multicomponent solitary waves in different combinations. Further on we investigate the formation of a self-trapped structure even without the stabilizing Gaussian mode and discuss its stability.