We describe the fabrication and characterization of optical waveguides formed in LiNbO3 by proton exchange in benzoic acid melts at 200–250 °C. Proton exchange, in LiNbO3 the replacement of lithium ions with protons, takes place when the substrate is immersed in the molten acid. We observe a surface increase in the refractive index of 0.12, for the extraordinary polarization only, with a step function index profile. This is the highest index increase obtainable to date for LiNbO3. Measured diffusion rates for x-cut crystals are 1.37 μm2/h at T = 249 °C and 0.37 μm2/h at T = 217 °C, so that very deep guides can be formed in short times. Diffusion is somewhat slower in the z direction. The process as described is not useful for y-cut crystals, since it damgaes this surface. Losses, measured on x-cut samples, were <0.5 dB/cm. All measurements were made at 0.633 μm.

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We report the observation of spatial optical solitons due to the Kerr nonlinearity in a planar glass waveguide and present measurements of the nonlinear response obtained by placing a pinhole at the output of the waveguide. For input intensities greater than that required for the fundamental soliton, we observe breakup of the output owing to the effect of two-photon absorption.

We report the experimental observation of interaction forces between two fundamental spatial optical solitons in a nonlinear glass waveguide. Both attraction and repulsion were observed, depending on the relative phase between the solitons.

We introduce a new electrowetting effect, continuous electrowetting (CEW), and show its advantages for applications to displays and other electro-optic devices. We demonstrate expe~mentally, by using CEW, fast and reversible electrowetting flow on the theoretically predIcted scale of -10 cm/s for -l-V driving voltage.