Transmission Of Subcarrier Multiplexed Signals Over Multimode Fibre Links Using Vertical Cavity Surface Emitting Lasers

Abstract

We show that low-cost multimode VCSElLs show sufficiently linear operation for operation in multimode fibre SCM systems. Dual source SCM systems are demonstrated with carrier frequencies up to 3GHz, indicating that multi-channel systems can readily be achieved for use in self-routing networks. Introduction Recently there has been much interest in the transmission of subcarrier multiplexed (SCM) signals over optical fibre, for example ini applications including cable television distribution and remote antenna addressing in mobile phone systems. SCM systems could also be employed in future computer interconnects and access netwoirks, where the ease of implementing carrier frequency changes readily allows for broadcasting and network reconfiguration. A schematic of such an interconnect, based on a bus-configuration, is shown infigure 1. Fig. 1: Schematic of SCM fibre optic network The dominant type of optical fibre currently installed in buildings is multimode fibre (MMF) [ 13 and hence there is interest in the potential of high speed SCM systems using this installed fibre base. As the insertion loss associate:d with MMF couplers and splitters can cause modal noise [2], low coherence light sources h,ave to employed in such systems. Self-pulsing laser diodes (SPLDs), which were developed for Compact Disk applications, are one option to meet this requirement and a MMF SCM link has been demonstrated using SPLDs [3]. However the