Ultrafast all-optical pattern matching using differential spin excitation and its application to bypass/drop self-routing for asynchronous optical packets

This paper presents a novel scheme for ultrafast all-optical pattern matching using the differential spin excitation in semiconductor multiple quantum wells (MQWs). In a demonstration of an all-optical pattern matching between two 100-Gb/s 16-bit optical packets, the contrast ratio of the photodiode (PD) output from the pattern matcher, between the pattern matched and the pattern-unmatched cases, was more than four for packets with a 2-dB power fluctuation. As an application of the pattern matcher to optical-packet-switched ring networks, bypass/drop self-routing is demonstrated for asynchronous 100-Gb/s 32-bit optical packets with 8-bit labels. In the experiment, a label of an incoming packet was compared to a local address (LA) given to a node in the optical domain. By changing the pattern of the LA packet instead of that of the incoming packet, the pattern matching was carried out for packets with various kinds of patterns. The contrast ratio of the PD output was more than six for all patterns.

I. Introduction

The EXPLOSIVE growth of Internet Protocol (IP) data traffic has led to an increasing demand for more capacity in communication networks [1]–[3]. In order to meet this demand, several photonic multiprotocol label switching (MPLS) technologies, such as generalized MPLS (GMPLS), optical burst switching (OBS), and optical packet switching (OPS), have been proposed. Among them, OPS is promising because OPS networks have advantages of great bandwidth efficiency, fine granularity, scalability, and flexibility. In OPS mesh networks, the label of an input packet is checked against address entries in the forwarding table at a node, and the packet is forwarded to an appropriate output port according to its destination [4]–[8]. In contrast, in ring networks, the label is compared with only one local address (LA) given to the node. When the label has the same pattern as the LA (a pattern-matched case), the packet is dropped, whereas the packet is forwarded to the next node in the ring network when the pattern of the label is different from that of the LA (a pattern-unmatched case) [9].