Optical packet switching and buffering by using all-optical signal processing methods

Abstract

We present a 1 2 all-optical packet switch. All the processing of the header information is carried out in the optical domain. The optical headers are recognized by employing the two-pulse correlation principle in a semiconductor laser amplifier in loop optical mirror (SLALOM) configuration. The processed header information is stored in an optical flip-flop memory that is based on a symmetric configuration of two coupled lasers. The optical flip-flop memory drives a wavelength routing switch that is based on cross-gain modulation in a semiconductor optical amplifier. We also present an alternative optical packet routing concept that can be used for all-optical buffering of data packets. In this case, an optical threshold function that is based on a asymmetric configuration of two coupled lasers is used to drive a wavelength routing switch. Experimental results are presented for both the 1 2 optical packet switch and the optical buffer switch. Index Terms-Optical flip-flop memories, optical header recognizing, optical packet switching, optical signal processing, wavelength conversion.

Architectures and Buffering for All-Optical Packet-Switched Cross-Connects

“…Furthermore, implementing wavelength conversion within the switching and buffering functional units results in very good signal quality because of the signal regeneration inherent in the all-optical architecture's building blocks [21]. An all-optical implementation of optical buffering is imperative to sustain good signal quality with a feedback architecture that will minimise the required buffer fibre.…”

“…Ref. [21] mentions strategies such as multiserver queues, reducing the link load, and implementing multiple-path routing schemes to reduce the degree of self-similarity.…”

“…The alloptical architectures proposed in this paper are based on the 1× N all-optical switches and N ×1 all-optical buffers as described in Ref. [21]. The 1 × N switches are implemented in parallel planes, each element handling one packet per timeslot, which means that crosstalk is minimised.…”

“…[21] (no electronic signal processing or control is assumed), fully shared buffers incorporating a buffer overflow algorithm in the wavelength domain is introduced, and these buffer architectures are investigated varying the following parameters: traffic load and models, the number of FDLs and FDL distributions, and the number of switch and buffer ports.…”

Multi-state optical memory based on serially interconnected lasers

“…O PTICAL memories have received considerable attention since they act as a fundamental building block for sophisticated digital optical signal processing [1], [2]. Many types of optical memories have been explored, which all have in common that optical storage elements with two states can be realized [3]- [7].…”