Abstract

The widespread popularity and penetration of the Internet has led to enormous increases in the volume of communication traffic, and this has intensified the need to increase the carrying capacity of wavelength division multiplexing (WDM) based broadband optical networks. Silica-based arrayed-waveguide grating (AWG) multi/demultiplexers will be the key components for such networks because of their excellent design flexibility, mass-producibility and high levels of performance regardless of channel count [1]. Adjacent crosstalk and dispersion in the AWGs degrades the transmission characteristics in high-speed optical networks, and so there is an urgent need to overcome these problems by improving the fabrication process and/or adjusting the AWGs externally. We describe a simple yet powerful method for improving the AWG performance externally. This is a photosensitive phase adjustment technique with which the arrayed waveguide part is irradiated with UV laser light through a metal mask. This approach enables us to reduce both the adjacent crosstalk and dispersion simultaneously for all channels [2,3].

© 2003 Optical Society of America