10 OAM × 16 Wavelengths Two-Layer Switch Based on an Integrated Mode Multiplexer for 19.2 Tb/s Data Traffic

Abstract

A two-layer switch exploiting orbital angular momentum (OAM) and wavelength of the light as switching domains is presented, aiming to increase the scalability with respect to the single-layer switches. The switch is able to accept 160 optical Gaussian data inputs on a 16-channel wavelength division multiplexing (WDM) grid and direct each input signals to different output ports exploiting 10 OAMs. The optical switch is based on an integrated OAM multiplexer followed by a compact OAM demultiplexer consisting of two refractive elements. Its experimental characterization confirmed a total enabled throughput of 19.2 Tb/s, thanks to the 30 GHz bandwidth available for each port. The switching time can be lower than 1 μs. The OAM switch power consumption, solely due to the thermal tuning of the OAM emitters, since the OAM demux is passive, is 1.35 mW/Gb/s. In the proposed switching architecture the number of active components, i.e., the power consumption, scales linear with the number of ports. This is favorable in comparison with single-layer switches that cascade e.g., 2 × 2 elementary blocks to obtain large port counts, which scale with the square of the number of ports. The switch accepts input and output signals with Gaussian phase profile that propagate through optical fibers and waveguides, thus making it compatible with standard telecom devices. The suitability of the switch to support real data-traffic is proved by successfully testing it with 10G Ethernet and fiber channel over Ethernet (FCoE) data and video traffic. A possible application scenario is represented by a data-center network where the switch can be used to create a low-power consumption network parallel to the network based on standard electronic routers, to manage large traffic flows.