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

Abstract

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 × 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.

Enabling capacity scaling in metro networks with multi band sliceable transceiver architectures

“…using tuneable laser source, TLS and Mach Zehnder modulator, MZM) trading off complexity/cost versus performance. 5,16 At the BVTx DSP block, orthogonal frequency division multiplexing (OFDM) is performed to increase the system flexibility enabling an efficient use of the available bandwidth. 5 Within the BVTx DSP block, data parallelization and mapping, training symbol (TS) insertion, inverse fast Fourier transform implementation, cyclic prefix (CP) insertion, serialization and radio frequency (RF) up-conversion processes are performed.…”

“…5,15 This flexible combination of the S-BVT building blocks enables to support multi-Tb/s transmission over the network, as demonstrated in. 16 A key element of the MB S-BVT is the MB optical aggregator/distributor that ideally consists of a programmable wavelength spectral switches (WSS), which can operate across multiple bands or either uses a combination of WSSs, each working at a certain band, together with combiners/splitters or other passive solutions. A more static and cheaper solution can be based on the adoption of passive optical filters, such as band pass filters (BPFs), at the expenses of loosing transceiver flexibility and scalability.…”

The Multiband over Spatial Division Multiplexing Sliceable Transceiver for Future Optical Networks

“…Different configurations can be adopted at the transmitter front-end of each MB S-BVT building block for modulation of the MB OFDM signals, such as IM, amplitude modulation or even IQ modulation [40]. Additionally, either external modulation (i.e., adopting Mach-Zehnder modulators-MZMs-and tuneable laser sources-TLSes) or direct modulation (i.e., using vertical cavity surface emitting lasers-VCSELs) can be adopted, trading-off performance versus cost/power consumption [22,41,42]. Finally, the different contributions are aggregated/distributed by means of an optical aggregator/distributor capable to allow operation across all the considered bands.…”

Impact of Device Topology on the Performance of High-Speed 1550 nm Wafer-Fused VCSELs

“…The maximum SM output power (with a side mode suppression ratio of 40-45 dB) is about 1.6-3.0 mW for VCSELs with 3-4 BTJs [24,[26][27][28]. The minimum DC power consumption is below 10 mW [24,29] due to the low differential resistance (~60 Ohm) and ultra-low threshold current (~1 mA for 4 µm buried tunnel junction devices). The 40 Gbps monolithic Coarse Wavelength Division Multiplexing (CWDM) C-band VCSEL arrays enable multicore, multi-level WDM for terabit board-to-board and rack-to-rack parallel optics (terabit-capacity active optical cable) [30].…”