Abstract

The current surge of interest in wavelength-division-multiplexed (WDM) networks is fueled, in part, by the rapid evolution of integrated-optic WDM technology. One important component for wavelength-routed networks¹ is the acoustooptic switch, which directs various nearby-spaced WDM channels, simultaneously and independently, to either of two ports. The classical acousto-optic filter response exhibits prominent sidelobes, which are the source of interchannel and interport cross talk among dense-packed WDM channels. Recently, several groups have successfully demonstrated significant sidelobe suppression by a range of techniques that apodize the acoustooptic interaction strength.^2-5 The apodization scheme based on the surface-acoustic-wave (SAW) coupler^2,3 places the active optical waveguide (which performs wavelength selection by a narrow-band polarization conversion) inside the remote arm of a SAW coupler, so that the SAW energy gradually builds up in the active region and then gradually departs, providing the smooth interaction profile required for apodization.

© 1994 Optical Society of America