Hybrid wired/wireless OFDM-PON with direct modulation of integrated lasers employing optical injection

In this paper the transmission of OFDM based wired/wireless services for hybrid PONs using direct modulation is studied. For overcoming the limitations imposed by direct modulation of cost effective low bandwidth laser transmitters we make use of novel monolithically integrated Discrete Mode lasers and optical injection. The system includes a wired OFDM signal operating at 12.5 Gb/s and three wireless signals delivering Long Term Evolution (LTE) services encoded with 16 QAM. We show experimentally how the limitations enforced in such hybrid systems when direct modulation is applied to low bandwidth lasers can be overcomed by employing optical injection. Results obtained for back to back transmission as well as over 50 km of fibre are presented, and system performance is evaluated for various relative power ratios of the wired/wireless signals.