Adaptive TFDM coherent PON: a flexible architecture with variable modulation formats and baud rates for next-generation optical access networks

This paper presents a highly adaptable and flexible TFDM coherent PON architecture, designed to address the diverse service requirements of next-generation optical access networks. We introduce an innovative approach featuring flexible modulation formats, adaptable baud rates, and dynamic link budget management, enabling the support of various service groups with tailored data rates and reach. Two experimental demonstrations validate the proposed TFDM coherent PON design. In the first demonstration, DSCs with 6.25 GBd DP-QPSK and DP-16QAM modulation provide 25 and 50 Gb/s data rates over 80 and 50 km reaches, respectively, while supporting both P2P link and P2MP links with up to 128 end users. The second demonstration further explores the adaptability of the system, with DSCs employing different baud rates: 6.25 GBd DP-QPSK, 12.5 GBd DP-16QAM, and 15.625 GBd DP-64QAM, delivering 25, 100, and 187.5 Gb/s data rates over varying distances and user counts. The second experiment also incorporates OOB communication channels for potential MAC control and OAM functionalities, showcasing the robust performance and versatility of the proposed TFDM coherent PON. This work extends our recent ECOC publication [European Conference on Optical Communication (ECOC) (Frankfurt, Germany, 2024), paper Tu3D.2], offering a more comprehensive view of the capabilities and future potential of TFDM-based coherent access networks.