April 24, 2026 -- Researchers in the group of Dr. Wesley Sacher at the Max Planck Institute of Microstructure Physics, in collaboration with Advanced Micro Foundry, have developed broadband, waveguide-coupled photodetectors in a foundry-fabricated silicon photonics platform for short (submicrometer) wavelengths. The devices consist of silicon nitride (SiN) nanophotonic waveguides coupled to silicon photodetectors, with operation relying on hybrid optical modes shared between the two materials. These modes are engineered through the waveguide dimensions to enable efficient broadband absorption. Published in Optics Express, the work demonstrates two detector variants collectively spanning a wavelength range of 400–955 nm, along with picoamp-scale dark currents, high-speed operation (up to 18 GHz), and avalanche-mode capability, enabling detection of weak optical signals.

In a broader context, short-wavelength (VIS + NIR) silicon photonics is opening doors to miniaturized, scalable optical systems, from biophotonics and sensing to quantum technologies and microdisplays. This work is part of a larger effort within Dr. Sacher’s group to support this breadth of applications with a versatile, foundry-fabricated platform spanning more than an octave in wavelength with high-performance components — thereby reducing the need for individually customized processes. As photodetection is a core functionality in photonic circuits, these results provide a key building block for advanced short-wavelength silicon photonic microsystems.

Ongoing work is integrating these components into photonic circuits for biosensors and implantable neurotechnologies, miniaturized light engines for smart glasses, and quantum photonics.