“…In Si photonics for the visible and NIR wavelength range, the optical waveguide is typically formed in a silicon nitride (SiN) or aluminum oxide (Al 2 O 3 ) layer surrounded by a silicon dioxide (SiO 2 ) cladding on a Si or silicon-on-insulator (SOI) substate. Thus far, on 100, 200, or 300-mm diameter Si wafers, visible/NIR photonic platforms with SiN 3 , 5 , 17 – 21 or Al 2 O 3 3 , 4 waveguides are usually passive, containing components such as gratings, power splitters, and interferometers, with waveguide phase-shifters tuned by the thermo-optic or strain-optic effect 5 , 22 – 24 . Post-fabrication processing and heterogeneous integration steps are used to incorporate liquid crystal phase-shifters 25 , lasers 26 , 27 , and photodetectors (PDs) 28 , 29 with SiN waveguides.…”