2009

N. Sapiens, A. Weissbrod, and A. J. Agranat, “Fast Electroholographic Switching,” Optics Letters , vol. 34, no. 3, pp. 353-355 , 2009.Abstract
Electroholographic switching with a rise time of 13 ns is henceforth presented. The switching was demonstrated in a potassium lithium tantalate crystal doped with copper and titanium with Tc=10 degrees C. The crystal was operated at 17 degrees C. The switching operation was done in the g11/g12 configuration, in which the Bragg condition remains fulfilled at all levels of the applied field. As electroholography is a wavelength-selective switching method, this opens the way for implementing optical packet switching and fast wavelength addressing schemes in optical fiber networks that apply wavelength division multiplexing.
A. Gumennik, G. Perepelitsa, A. Israel, and A. J. Agranat, “A tunable channel waveguide array fabricated by the implantations of Heions in an electrooptical KLTN substrate,” Optics Express, vol. 17, no. 8, pp. 5919-6251, 2009.Abstract
An electrooptical channel waveguide array was constructed in potassium lithium tantalate niobate substrate by the implantation of He+ ions at high energies. The array was fabricated by two successive implantation sessions at 1.6 MeV and 1.2 MeV through a comb-like stopping mask that limited the implanted ions to penetrate the substrate in 1 ?m wide stripes periodically distributed at 3.5 ?m intervals. This generated a grating of amorphized stripes with reduced refractive index. This was followed by a uniform implantation of He+ ions at 1.8 MeV which created a bottom cladding layer below the array. Wave propagation in the array was studied by focusing a light beam at 636 nm into the central channel, and observing the wavefront it created at the output plane of the array. It was found that applying an electric field across the array strongly affects the coupling between adjacent channels and governs the width of the wavefront at the output plane.