Integrated silicon multifunctional mode-division multiplexing system.

Chip-scale optical interconnects have been widely investigated using the wavelength-division multiplexing (WDM) technology, while it has been rarely reported using the mode-division multiplexing (MDM) technology that further improves communication capacity by using multiple spatial mode channels. On the other hand, to achieve large-bandwidth multi-core computing, a flexible and reconfigurable network is highly desired. Here, we proposed and demonstrated a 4 × 4 chip-scale multifunctional MDM system to realize the interconnects among 4 dual-core computing processors. The proposed system integrates fundamental components such as high-speed modulator arrays, multimode switches, and large-bandwidth photodetector arrays, in addition to various multimode devices. The thermal heaters are utilized to achieve multifunctional routing, including inter-mode and inter-path cases. The transmission of 10 Gb/s On-Off Keying (OOK) signal is verified, which demonstrates the reconfigurable inter-core and inter-processor interconnects.