Nature Communications: Integrated van der Waals waveguides enable broadband all-optical nonlinear photonic circuits

About

All-optical neural networks promise high-speed and energy-efficient computing, but implementing nonlinear activation directly in the optical domain remains a major challenge. Many existing approaches rely on electronic conversion, slow tuning mechanisms, or wavelength-sensitive resonant structures, which limits the scalability of integrated photonic computing systems. In our new Nature Communications paper, “Integrated van der Waals waveguides for all-optical nonlinear photonic circuits,” we demonstrate an integrated MoS₂ waveguide platform for broadband all-optical nonlinear activation.
The core idea is to use vertically grown van der Waals MoS₂ waveguides as both optical transmission paths and nonlinear processing units. By increasing exposed edge states and defect-assisted sub-bandgap absorption, the waveguides provide strong saturable absorption in the telecommunication bands while remaining compatible with on-chip integration. This enables resonance-free optical activation directly inside the photonic circuit, avoiding separate electronic nonlinear units.
The platform operates across both the O-band and C-band, with response speeds approaching 10 ps. We further benchmarked the measured optical activation function in neural network inference tasks, including handwritten digit and natural image classification. The MoS₂-based activation achieved performance comparable to mainstream digital activation functions across different network architectures and quantization settings, with less than 0.5% accuracy degradation on MNIST and less than 1% variation across CIFAR-10 settings.
These results provide a practical route toward compact, broadband, and manufacturable nonlinear building blocks for all-optical neural networks. By integrating signal transmission and nonlinear activation within the same van der Waals waveguide platform, this work advances scalable photonic computing hardware for future high-speed AI systems.
 

Full text link: Integrated van der Waals waveguides for all-optical nonlinear photonic circuits
Ref: Zhang, X., et al. “Integrated van der Waals waveguides for all-optical nonlinear photonic circuits.” Nature Communications (2026).