WDM-compatible multimode optical switching system-on-chip

Abstract

The development of optical interconnect techniques greatly expands the communication bandwidth and decreases the power consumption at the same time. It provides a prospective solution for both intra-chip and inter-chip links. Herein reported is an integrated wavelength-division multiplexing (WDM)-compatible multimode optical switching system-on-chip (SoC) for large-capacity optical switching among processors. The interfaces for the input and output of the processor signals are electrical, and the on-chip data transmission and switching process are optical. It includes silicon-based microring optical modulator arrays, mode multiplexers/de-multiplexers, optical switches, microring wavelength de-multiplexers and germanium-silicon high-speed photodetectors. By introducing external multi-wavelength laser sources, the SoC achieved the function of on-chip WDM and mode-division multiplexing (MDM) hybrid-signal data transmission and switching on a standard silicon photonics platform. As a proof of concept, signals with a 25 Gbps data rate are implemented on each microring modulator of the fabricated SoC. We illustrated 25 × 3 × 2 Gbps on-chip data throughput with two-by-two multimode switching functionality through implementing three wavelength-channels and two mode-channel hybrid-multiplexed signals for each multimode transmission waveguide. The architecture of the SoC is flexible to scale, both for the number of supported processors and the data throughput. The demonstration paves the way to a large-capacity multimode optical switching SoC.

Optically Multiplexed Systems: Wavelength Division Multiplexing

“…Like in [14], WDM is used for optical beam steering, which is archived using photonic crystal waveguide and an integrated version of WDM in coupled micro-ring Muxs. Another field where WDM has found application is inter-chip links, as in [15] where micro-ring wavelength demultiplexers are used.…”

On-chip silicon photonic controllable 2 × 2 four-mode waveguide switch

“…However, both of those structures need asymmetric adiabatic couplers for realizing the (de)multiplexing functionalities in a multimode bus waveguide and Mach–Zehnder interferometers (MZI) for switching operation leading a large footprint and relatively complicated mechanism. Some other proposals for multimode switches either based on multiplexers/demultiplexers and waveguide crossing structures following Benes topologies 29 , 30 or use lots of relatively complicated microring resonators and waveguide crossing elements.…”

Compact, Highly Efficient, and Controllable Simultaneous 2 × 2 Three-Mode Silicon Photonic Switch in the Continuum Band

“…However, such structures either need many asymmetric adiabatic couplers for deploying the (de)multiplexing functionalities before the switching operation or use indispensable waveguide crossing elements. Other approaches utilize the Benes topology by cascading multistage, leading to large footprints and comparatively complicated mechanisms [9], [26], [27]. This paper proposes a compact 2×2 three-mode optical switch design allowing the simultaneous switching operation of three modes without needing mode multiplexers and fundamental mode switches.…”