Novel Wavelength Distribution Nodes Based on Photonic Integrated EDWA and SOA-Based WSS for Metro-Access Networks

This paper presents an experimental investigation of a scalable, reconfigurable wavelength distribution node (WDN) architecture for next-generation optical metro-access networks, capable of dynamically routing coherent Wavelength Division Multiplexing (WDM) channels at multi-Tbps levels, with 800 Gbps per channel. The proposed architecture leverages novel photonic integrated erbium-doped waveguide amplifiers (EDWAs) combined with Semiconductor Optical Amplifier (SOA)-based 1×N Wavelength Selective Switches (WSS), facilitating dynamic add/drop capabilities essential for flexible metro-access deployments. Three experiments validated the architecture's transmission performance and scalability. The first experiment demonstrated successful add/drop and drop&continue dynamic switching of six 800 Gbps WDM channels, achieving an aggregate throughput of 4.8 Tbps with an average Optical Signal-to-Noise Ratio (OSNR) degradation of only 0.55 dB after one node, and 2.4 dB after cascading two nodes over a 55.2 km link. The second experiment confirmed error-free transmission of eight 800 Gbps WDM channels, recording a maximum OSNR penalty variation among channels of 3.56 dB. The third experiment evaluated scalability using a 1×4 for WDN1, 1×16 WSS for WDN2 configuration, achieving error-free transmission serving up to 64 access points at 800 Gbps per channel, with a cumulative OSNR penalty of 7.44 dB after cascading two WDN nodes. These results demonstrate the feasibility and high performance of integrated photonic solutions in meeting future 6G network demands.