Experimental demonstration of a metro area network with terabit-capable sliceable bit-rate-variable transceivers using directly modulated VCSELs and coherent detection

Disaggregation in optical networks is particularly relevant to be considered for the deployment of 5G services and towards the support of 6G. Particularly in the metro area network (MAN), this is especially crucial, as is the adoption of suitable photonic technologies enabling dense integration to design a sustainable network architecture. Furthermore, to dynamically allocate the ever-increasing traffic, supporting multiterabit capacity, an optimal usage of the available resources by properly exploiting the multiple dimensions (including the spectral and spatial ones), with programmable and adaptive data plane solutions, is key. In this work, we assess the capabilities of a disaggregated MAN that relies on new photonic devices, node architectures, and sliceable bandwidth/bit-rate-variable transceivers, approaching wavelength division multiplexing and space division multiplexing. A hierarchical network topology is attained and the feasibility of a cross-hierarchy optical continuum is demonstrated. In fact, we experimentally demonstrate the successful transmission of multiterabits/second capacity across multiple nodes corresponding to different hierarchy levels that have different implementation schemes and support different technologies. For the top tier hierarchy level nodes, we demonstrate the transmission of up to
${8} \times {11} = {88}$
spatial/spectral channels, for a total capacity of 1.676 Tb/s, employing a node architecture able to handle up to 2560 spatial/spectral channels at different aggregation levels and granularities.