Modular and scalable photonic integrated multi-band wavelength-selective switch

Today’s optical transmission landscape is seeing a rapid increase in resource demand, due to bandwidth-intensive applications, emerging standards, such as 5G, as well as the expansion of the Internet-of-Things (IoT) paradigm. This requires an expansion of the current optical network infrastructure and capability, accommodating the increasing demand [1]. From the network operator standpoint, two main solutions are available: new infrastructure can be deployed, which represents the expensive solution, or the residual capacity of the existing network can be exploited through multi-band paradigms, which represents the more cost-effective solution [2]. To achieve the full utilization of the remaining available fiber spectrum, new technologies such as Band-Division Multiplexing (BDM) must be enabled on top of the already existing Wavelength-Division Multiplexing (WDM) based network. This requires switching and filtering elements suited for an ultra-wide bandwidth of operation, allowing consistent performances in the whole needed spectrum. For this purpose, photonic integrated circuits (PICs) represent an ideal solution, as they provide a large bandwidth of operation while maintaining low footprint, cost, and power consumption. To this end, we propose a fully integrated modular wavelength-selective switch (WSS), able to independently route each of the input signal channels towards the desired output port, operating on the S+C+L optical transmission windows.