Design and performance of a low crosstalk directional coupler switch

Abstract
A directional coupler switch having an extinction ratio better than 35 dB has been fabricated using Ti-indiffused waveguides. Detailed measurements of voltage, wavelength and temperature response and of the mode intensity profile are given. A computer model which allows inaccuracies in fabrication to be included is presented, with results relating extinction ratio to waveguide separation angle and mode confinement.