All-optical wavelength reuse with simultaneous upstream data and PPS timing signal transfer for flexible 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 downstream data from 6.2 dB to 839.1 mdB. This allows for data rewrite and wavelength reuse for upstream 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 simultaneous carrier reuse and PPS clock upstream transfer. PPS jitter stability of 1.01 × 10-08 ns and 6.64 × 10-08 ns are attained respectively. This work offers a convenient all-optical wavelength reuse solutions for optical access networks.