Optical Buffering and Switching for Optical Packet Switching

Abstract

Abstract:We describe the design and initial results of an all-optical buffered 40 Gb/s packet switch. Dynamic packet forwarding is illustrated and specific attention is directed to buffering. We assess the challenges in meeting the requirements for optical buffering devices. Slow light and delay line buffering approaches are described and several recent results and issues are summarized.

Optical RAM and integrated optical memories: a survey

“…The most typical way to resolve contention relies on the use of buffers to delay one of the two contending packets until the desired outgoing port again has an available timeslot. Realizing optical buffers for storing optical packets in OPS fabric demonstrations was widely researched in the early 2000 s, often residing in the areas of recirculating fiber loops [3][4][5] or fiber delay lines [6][7][8][9] to circumvent the absence of true optical RAM buffers. However, these setups can offer only a limited buffering time; hence, the quest toward real optical RAM buffers soon became a necessity and was pioneered in a big R&D initiative in Japan [36][37][38][39]128 , promoting for the first time the use of InP photonic crystal nanocavities for packet buffering purposes in OPS fabrics.…”

“…Two decades later, the first optical set-reset flip-flop (SR-FF) mechanism was launched in 1985, achieving response times of <1 ns 2 , while in the next few years, research efforts mainly focused on temporarily confining light to a continuous loop inside a medium 1,[3][4][5] . As fiber optics gradually turned into a mainstream telecom transmission platform, the research interest in optical memories experienced a significant boost in view of the possible high-speed optical signal processing applications, with a variety of schemes such as optical delay lines [6][7][8][9] , fiber-loop-based and slowlight optical buffers 10,11 and, more recently, all-optical flip-flop (AOFF) devices being introduced for packet-level contention resolution purposes 12,13 .…”

Improving the SOA Switching Speed of Wavelength-Striped Optical Packets Using Multipulse Current Injection

“…OPS comprises a packet-based approach that can transmit extremely high-bandwidth optical messages with low latency end-to-end among the optical network's input and output ports. The semiconductor optical amplifier (SOA) is a key optical device for implementing OPS networks, due to its fast switching speeds, high extinction ratios, data transparency, broad gain spectrum, and ability to be integrated on a chip [1]. SOAs may be deployed as amplifiers, add-drop optical links, and wavelength converters in wavelength-division-multiplexed (WDM) networks.…”