Abstract

The goal of dense wavelength-division multiplexed (WDM) networks is to to expand the capacity of high throughput optical networks through parallel processing in the wavelength domain. Thinking of wavelength slots as independent information-bearing channels, one must find means to add or drop wavelengths into the network or, more generally, to overlay independent routing patterns for each separate wavelength channel on top of a single physical fiber network. By far, the integrated acousto-optic filter (AOF) [1] is the most sophisticated component for wavelength-selective filtering and switching in wavelength-routed optical networks. The unique feature of the AOF is its ability to filter or route many wavelength channels simultaneously, unlike other single-state filters, such as the Fabry-Perot and Mach-Zehnder cascade. In this paper we demonstrate a technique to construct very low crosstalk 1×2 and 2×2 AO switches by means of switch dilation [2]. Dilation allows one to obtain nearly ideal switch performance by cascading filter subcomponents, in such a way as to reduce first-order crosstalk to second order. The price paid is switch complexity.

© 1993 Optical Society of America