On-chip multi-band mode-division multiplexed optical interconnect using ultra-broadband inverse-designed digital metamaterials
TL;DR
The first multi-band mode multiplexer (MUX) built on a digital-metamaterial structure, supporting the first three TE modes within a 6 × 4.8 µm² footprint. It keeps an exceptionally flat response across 1500–2100 nm, with measured insertion loss below 4.3 / 4.0 dB and crosstalk below −11.6 / −11.3 dB in the 1525–1585 nm and 1940–2040 nm bands, enabling 3-mode × 180 Gb/s at 1.55 µm and a record 3-mode × 114 Gb/s at 2 µm.
Background
Combining mode-division multiplexing (MDM) with wavelength-division multiplexing (WDM) is a compelling way to raise the shoreline density of on-chip optical interconnects. But existing on-chip MDM systems struggle to deliver large optical bandwidth, multi-band operation and ultra-compactness at the same time.
Device & Results
We introduce the first multi-band mode multiplexer based on a digital-metamaterial structure supporting the first three-order TE modes, ultra-compact at 6 × 4.8 µm² with a flat spectral response across 1500–2100 nm.
Highlights
- First multi-band mode multiplexer based on a digital-metamaterial structure (3 TE modes, 6 × 4.8 µm²)
- Flat 1500–2100 nm spectral response (variation < 0.94 dB)
- 3 modes × 180 Gb/s at 1.55 µm; record 3 modes × 114 Gb/s at 2 µm
- Selected as Editor's Pick in Photonics Research
Citation
A. Sun et al., "On-chip multi-band mode-division multiplexed optical interconnect using ultra-broadband inverse-designed digital metamaterials," Photonics Research, 13(10), 2025.