Optical packet switches: a comparison of designs

Many optical packet switches have been proposed to facilitate the widespread deployment of broadband integrated services digital networks. Although optical packet switches offer data rate and format transparency, and high switching speed, their performance strongly depends on optical device technology. This paper discusses the fundamental limitations of a selected number of guided wave optical packet switches; a comparison in terms of the number of components, buffering capability, control complexity and switching technology is made. The main limitation of these optical packet switches is optical splitting/combining loss. One approach to reduce this loss is the use of arrayed-waveguide gratings (AWGs). An AWG having a crosstalk level as low as -30 dB can be used as a demultiplexer, a multiplexer and an interconnect. An AWG is proposed as the core of an optical packet switch.