Theoretical and experimental studies on active Y-junctions in optical waveguides

Abstract

Theoretical and experimental results are presented on single-mode <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Y</tex> -junction switching devices in Ti-diffused LiNbO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> waveguides. The operation of these devices relies on a redistribution, by means of the elcctrooptic effect, of the power in the input waveguide before it is transmitted to the output waveguides of the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Y</tex> -junction. Measured performance is shown to be predicted satisfactorily by a theoretical model of a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Y</tex> -junction in homogeneous, planar waveguide. Transmission losses of less than 1 dB and extinction ratios of about 15 dB have been obtained in a device with a junction half-angle of 0.57°.