47.5 GHz Membrane-III-V-on-Si Directly Modulated Laser for Sub-pJ/bit 100-Gbps Transmission

• Published in: Photonics
• Main Authors: Nikolaos-Panteleimon (Pandelis) Diamantopoulos, Suguru Yamaoka, Takuro Fujii, Hidetaka Nishi, Koji Takeda, Tai Tsuchizawa, Takaaki Kakitsuka, Shinji Matsuo
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2021
• Subjects: directly modulated lasers; III-V on Si; photon-photon resonance; data centers; Applied optics. Photonics; TA1501-1820; DML
• Online Access: https://doi.org/10.3390/photonics8020031; https://doaj.org/article/678b746b4b974f7f8ad2240163dd37af

Near-future upgrades of intra data center networks and high-performance computing systems would require optical interconnects capable of operating at beyond 100 Gbps/lane. In order for this evolution to be achieved in a sustainable way, high-speed yet energy-efficient transceivers are in need. Towards this direction we have previously demonstrated directly-modulated lasers (DMLs) capable of operating at 50 Gbps/lane with sub-pJ/bit efficiencies based on our novel membrane-III-V-on-Si technology. However, there exists an inherent tradeoff between modulation speed and power consumption due to the carrier-photon dynamics in DMLs. In this work, we alleviate this tradeoff by introducing photon–photon resonance dynamics in our energy-efficient membrane DMLs-on-Si design and demonstrate a device with a maximum 3-dB bandwidth of 47.5 GHz. This denotes a bandwidth increase of more than 2x times compared to our previous membrane DMLs-on-Si. Moreover, the DML is capable of delivering 60-GBaud PAM-4 signals under Ethernet’s KP4-FEC threshold (net data rate of 113.42 Gbps) over 2-km of standard single-mode fiber transmission. DC energy-efficiencies of 0.17 pJ/bit at 25 °C and 0.34 pJ/bit at 50 °C have been achieved for the > 100-Gbps signals. Deploying such DMLs in an integrated multichannel transceiver should ensure a smooth evolution towards Terabit-class Ethernet links and on-board optics subsystems.