Abstract

Multistage networks, such as the Omega/shuffle-exchange network, Clos/Benes network, etc., are widely used in telecommunications and parallel signal processing today. An optical implementation of these networks is desirable because of its high data rates, low crosstalk, and the feasibility of 2-D structures in optics. Shuffling interconnections and bypass/exchange switches are two basic building blocks in a multi stage network. The free-space optical perfect shuffle, 2-D folded perfect shuffle, and 2-D separable shuffle have been described.¹-⁴ Stirk and Athale proposed an optical implementation for bypass/exchange switch based on latching logic⁵. We present several optoelectronic designs for single and multistage 2×2 bypass/exchange switch modules. One design is for a general 2×2 single stage circuit switched module which can perform bypass, exchange, and broadcasting functions. In this module, control and power are supplied at wavelength λ₂, while data are passed at wavelength λ₁. A second design is for a bypass/exchange switch in which both data and control are carried at λ₁, while power is supplied at λ₂. This design can operate in both packet or circuit switched mode. Finally, we discuss modules for use in multistage networks. In this application, signal routing information can be inserted from a controller at each stage, or the data can be self-routed by headers attached to each data packet. We also present a multistage bypass/exchange 2×2 switch capable of central control or self-routing.

© 1989 Optical Society of America