2025 · 03· Nature Communications · 16:2372· Co-first author· IF 14.7

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

A. Sun*, S. Xing*, et al. (* equal contribution)
Fudan University · Zhangjiang Lab

TL;DR A high-capacity on-chip optical interconnect that jointly multiplexes wavelength, mode and higher-order modulation, demonstrating 38.2 Tb/s aggregate capacity over a single silicon waveguide (5 modes × 88 wavelengths, up to PAM-8). The enabling element is a compact, broadband, fabrication-robust mode (de)multiplexer obtained by an edge-guided inverse-design method on a digital metamaterial.

Multi-dimensional multiplexed optical interconnect

Background

As large-scale data centers and optically-interconnected compute systems demand exponentially higher link capacity, scaling on-chip optical bandwidth on wavelength alone is no longer sufficient. Multi-dimensional multiplexing — using the spatial (mode) dimension together with wavelength and higher-order modulation — is the key path to multiplying the capacity carried by a single silicon waveguide.

Architecture & Method

We construct a high-capacity on-chip optical interconnect that simultaneously multiplexes wavelength-division, mode-division and higher-order modulation on a single silicon waveguide. The enabling building block is a compact, ultra-broadband, low-crosstalk mode (de)multiplexer realized by an edge-guided inverse-design method on a digital metamaterial.

Highlights

38.2 Tb/s aggregate transmission capacity demonstrated end-to-end on a single silicon waveguide
5 spatial modes × 88 wavelength channels, with up to PAM-8 modulation per channel
Per-wavelength capacity reaches 1.62 Tb/s — extending into the 2 Tb/s coherent regime
Edge-guided inverse design produces broadband, low-loss mode (de)multiplexers compatible with standard CMOS foundry process

Citation

A. Sun*, S. Xing* et al., "Edge-guided inverse design of digital metamaterial-based mode multiplexers for high-capacity multi-dimensional optical interconnect," Nature Communications, 16:2372, 2025.