Abstract

Although a symmetric directional coupler, which is composed of two identical parallel waveguides, is quite attractive as a constituent element for a large scale N × N star coupler, its use in wavelength multiplexed systems is limited due to its narrow operating wavelength window. As asymmetric directional coupler composed of two parallel unidentical waveguides is proposed, and its theoretically predicted wideband operation was confirmed experimentally in uniform and alternating Δβ (Ref. 1) configurations by fabricated high silica optical waveguide couplers.

© 1990 Optical Society of America