Novel all-optical switching node in a self-routed wavelength-addressable network (SWANet)

All-optical networks promise to allow high-bandwidth applications to be provided to many users simultaneously.1-3 We propose a novel all-optical wavelength-routed switching network based on a new address-coding scheme.4 This scheme uses a serial combination of wavelengths as the routing tag of the data packet, as illustrated in Fig. 1. All-optical switching can be accomplished by sensing the wavelength of the routing tag without converting the high-speed data to electronic form. Self-routing is exercised by sensing the wavelength content of the appropriate section of the routing tag at each switching stage of a multistage switching network; each switching node performs a latching function that directs the packet to the corresponding output port until the final destination is reached. The key advantage of this scheme is that a large number of address codes can be accommodated, not limited by the number of available wavelengths as in conventional wavelength- division-multiplexed networks. Further, high-speed data transmission can be realized by using low-speed control channels transmitted on the same fiber.