All-optical wavelength reuse with simultaneousupstream data and PPS timing signal transfer forflexible optical access networks

Abstract

All-optical wavelength reuse is a viable approach for realization of low cost colourless ONUs. We experimentally demonstrate a novel all-optical wavelength reuse technique with simultaneous upstream data and pulse-per-second signal transfer, exploiting EDFA gain saturation with a holding beam. A DFB laser is modulated with 8.5 Gbps data and transmitted downstream over 24.7 km fibre. A saturated EDFA located at the ONU is adopted to reduce the extinction ratio of the downstreamdatafrom6.2dBto839.1mdB.Thisallowsfordatarewriteandwavelengthreuseforupstream transmission. Receiver sensitivities of −20.19 dBm and −19.60 dBm are achieved at back-to-back analysis and 24.7 km downstream link respectively. A holding beam is further exploited to attain simultaneouscarrierreuseandPPSclockupstreamtransfer.PPSjitterstabilityof1.01×10−08nsand 6.64×10−08nsareattainedrespectively.Thisworkoffersaconvenientall-opticalwavelengthreuse solutionsforopticalaccessnetworks.