Lithium Niobate Slab Research Articles

Interactions between one-dimensionalquadratic soliton-like beams

The interaction between two quadratic soliton-like beams was investigated for beams launched parallel to one another, and at small crossing angles. The experiments were performed in titanium in-diffused lithium niobate slab waveguides near a Type I phase-matching condition for second harmonic generation (SHG). Only beams at the fundamental frequency were launched and the second harmonic required for quadratic soliton formation was generated upon propagation into the waveguide. The results of the interaction were found to depend on the relative phase between the input fundamental beams, the net phase mismatch for SHG and on the beam crossing angle. Good agreement with numerical simulations of the different interactions was found. In general, the results of the interactions were similar to those found in saturable Kerr-like media.

Observation of dynamic photorefractive effect in lithium niobate waveguides

We report the experimental observation of a transitory state during the build-up of photorefractive effects in lithium niobate slab waveguides. By prism coupling light into and out of the structure, we observed a relatively fast time-dependent spatial distortion of the output coupled beam. The experimental results are interpreted qualitatively in terms of a dynamic-state photorefractive effect, due to the photo-excitation of impurity-localized dipoles. A model of this mechanism is briefly outlined in conjunction with the formation of a holographic grating due to in-plane light scattering.

A New Technique for Analysing Light Propagation in Lithium Niobate Slab Waveguides

Abstract An accurate method is proposed for evaluating the index dispersion and field distribution within a Ti: LiNbO3 slab waveguide. The derivation is based on analytical solutions of the wave equation. The propagation characteristics are obtained using Fuchs' theorem which allows the solution of the boundary-value problem, with the desired degree of accuracy, for any analytically expressed refractive-index profile, even in the cut-off regions. Only a few minutes of computer time are required to draw the dispersion curves and field distribution using a VAX system.