Complete compensation of pulse broadening in an amplifier-based slow light system using a nonlinear regeneration element

Sanghooon Chin,Miguel Gonzalez-Herraez,Luc Thévenaz

doi:10.1364/oe.17.021910

Abstract

We experimentally demonstrate complete compensation of pulse broadening in an amplifier-based slow light system. The configuration of the delay line basically consists of two stages: a conventional Brillouin slow light system and a nonlinear regeneration element. Signal pulses experienced both time delay and temporal broadening through the Brillouin delay line and then the delayed pulses were delivered into a nonlinear optical loop mirror. Due to the nonlinear response of the transmission of the fiber loop, the inevitably broadened pulses were moderately compressed in the output of the loop, without loss in the capacity to delay the pulses. The overall result is that, for the maximum delay, the width of the pulse could be kept below the input width while the time delays introduced by the slow light element were preserved. Using this delay line, a signal pulse with duration of 27 ns at full width at half maximum was delayed up to 1.3-bits without suffering from signal distortion.

Highlights

Slow light has important potential implications in modern technologies oriented towards high capacity networks such as all-optical signal processing, optical buffers, optical memories and quantum computing [1]
The Brillouin characteristics of this fiber were measured, showing a Brillouin shift of 10.8 GHz and an SBS gain bandwidth of 27 MHz A commercial distributed feedback (DFB) laser diode operating at 1532 nm was used as the light source and its output was split using an optical coupler
We have experimentally demonstrated a novel configuration to realize a SBS slow light delay line with essentially no pulse broadening

Summary

Introduction

Slow light has important potential implications in modern technologies oriented towards high capacity networks such as all-optical signal processing, optical buffers, optical memories and quantum computing [1]. Our demonstration is based on an all-fiber setup, rendering the system very attractive for future applications in the field of optical communications It makes use of the combination of a conventional Stimulated Brillouin Scattering (SBS)-based linear slow light system and a nonlinear optical fiber loop mirror (NOLM) as the broadening compensation element. We could effectively achieve no pulse broadening for a fractional delay above unity in the SBS slow light delay line This regeneration element can eliminate most of the background noise introduced by the Brillouin amplifier when the pulse is “off”, improving the contrast between the ones and the zeros in a transmission system. There is in principle no limitation to cascade this system and achieve large fractional delays with minimized distortion

Principle

12 Km DSF

Experiments and results

Conclusions