Monolithically Integrated Dual-Output DEML for Full Duplex DPSK-ASK and DPSK-SSB ONU in Ultra-Dense Channel Spaced Access Network

Ultra-dense access network attracts people's attention recently; however, until now it is difficult to implement it commercially owing to cost, footprint, and the traditional complexity of coherent receiver. Single laser, especially integrated laser-based optical network unit (ONU) provides a potential system for simplifying the ONU. Here, we show a 2.5-Gb/s/user bidirectional transmission with 5-GHz channel spacing between uplink and downlink for ultra-dense wavelength division multiplexed. A monolithic integration on dual output dual electro-absorption modulated laser (DEML)-based ONU for "λ-to-the-user" network is demonstrated. Furthermore, bidirectional differential phase-shift keying (DPSK)-amplitude shift keying and DPSK-single side band transmission with low-footprint, monolithically integrated DEML at ONU are also tested.