All-optical 3R regeneration for agile all-photonic networks

Abstract

Transmission impairments degrade the quality of optical signals, ultimately limiting the achievable transmission distance. Optical 3R regenerators provide an effective means of coping with transmission impairments by restoring the quality of optical signals through reamplification, reshaping, and retiming (3Rs), thereby enabling reliable transmission over long distances. Beyond the 3Rs, however, regenerators must also be able to operate within the practical constraints of the network. The specific network of interest in this thesis is referred to as an agile all-photonic network (AAPN).

In AAPNs, traffic consists of optical packets that are routed through the core of the network without undergoing optical-to-electrical conversion for signal processing (e.g., 3R regeneration). As a result, 3R regeneration must be performed all-optically, otherwise known as all-optical 3R regeneration (AO-3R). Although a variety of AO-3R techniques have been demonstrated, none have been specifically designed to operate within the practical constraints of AAPNs.

In this thesis, a 10 Gb/s all-optical 3R regeneration (AO-3R) technique is proposed, specifically designed to operate within the practical constraints of AAPNs. The technique performs AO-3R in a novel 2-stage design. In the first stage, all-optical retiming is achieved using a self-pulsating distributed feedback laser (SP-DFBL) for all-optical clock recovery and cross-phase modulation (XPM) in highly nonlinear fiber (HNLF) with offset spectral slicing for the retiming. In the second stage, all-optical reshaping (and reamplification) is achieved using self-phase modulation (SPM) in HNLF with offset spectral slicing.

Experimental assessment of the AO-3R system performance yields excellent results. In particular, AO-3R is shown to improve the performance of input signals degraded by transmission impairments, such as amplified spontaneous emission (ASE) noise, while providing low sensitivity to input signal properties, such as the state-of-polarization. Furthermore, AO-3R is shown to successfully achieve its ultimate goal for AAPNs – the regeneration of optical packets.