Prototyping of silicon nitride photonic integrated circuits for visible and near-infrared applications

We describe a prototyping process for silicon nitride photonic integrated circuits, targeting applications in the visible and near-infrared wavelength ranges. The platform is based on direct-write electron beam lithography technology and provides a route toward the rapid fabrication of passive and thermo-optic active photonic devices. The fabrication turnaround time is on the order of several weeks, and critical feature sizes are demonstrated down to 100 nm which enables the fabrication of subwavelength metastructures. Two waveguiding material thicknesses have been demonstrated, 150 nm for visible light applications and 400 nm for infrared.