Monolithically Integrated Multilayer Silicon Nitride-on-Silicon Waveguide Platforms for 3-D Photonic Circuits and Devices

Key Points

• To review the development of monolithic multilayer silicon nitride-on-silicon platforms designed for very large-scale 3D photonic integrated circuits operating across telecommunication bands.
• Monolithically integrated one or more silicon nitride waveguide layers directly onto a base silicon photonic layer to create three-layer platforms for the O- and SCL-bands.
• Designed and fabricated low-loss interlayer transitions, ultralow-loss waveguide crossings, and multilevel (bilevel and trilevel) grating couplers for optical fiber interfacing.
• Combined passive silicon nitride and silicon structures with active elements, including high-efficiency optical modulators, photodetectors, and thermal tuners on a single platform.
• Achieved low-loss vertical transitions between photonic layers and ultralow-loss waveguide crossings capable of supporting networks with hundreds to thousands of intersections.
• Demonstrated efficient fiber-to-chip coupling across the O- and SCL-bands using bilevel and trilevel grating coupler geometries.
• Successfully co-integrated passive multi-waveguide routing networks with active modulators, photodetectors, and thermal tuning elements.