Edge-guided inverse design of digital metamaterial-based mode multiplexers for high-capacity multi-dimensional interconnect

TL;DR

This paper demonstrates a high-capacity optical interconnect system using edge-guided inverse design of digital metamaterial mode multiplexers, achieving record data rates for scalable computing applications.

Contribution

It introduces an edge-guided inverse design method for digital metamaterial waveguides, enabling robust, high-efficiency mode multiplexers for ultra-high-capacity optical interconnects.

Findings

Achieved 1.62 Tbit/s single-wavelength capacity.

Realized 38.2 Tbit/s multi-dimensional interconnect capacity.

Demonstrated high-order modulation formats up to 8-PAM.

Abstract

The escalating demands of compute-intensive applications urgently necessitate the adoption of optical interconnect technologies to overcome bottlenecks in scaling computing systems. This requires fully exploiting the inherent parallelism of light across scalable dimensions for data loading. Here we experimentally demonstrate a synergy of wavelength- and mode- multiplexing combined with high-order modulation formats to achieve multi-tens-of-terabits-per-second optical interconnects using foundry-compatible silicon photonic circuits. Implementing an edge-guided analog-and-digital optimization method that integrates high efficiency with fabrication robustness, we achieve the inverse design of mode multiplexers based on digital metamaterial waveguides. Furthermore, we employ a packaged five-mode multiplexing chip, achieving a single-wavelength interconnect capacity of 1.62 Tbit s-1 and a record-setting multi-dimensional interconnect capacity of 38.2 Tbit s-1 across 5 modes and 88 wavelength channels, with high-order formats up to 8-ary pulse-amplitude-modulation (PAM). This study highlights the transformative potential of optical interconnect technologies to surmount the constraints of electronic links, thus setting the stage for next-generation datacenter and optical compute interconnects.