Visible-light silicon nitride waveguide devices and implantable neurophotonic probes on thinned 200 mm silicon wafers.

We present passive, visible light silicon nitride waveguides fabricated on approximate to 100 mu m thick 200 mm silicon wafers using deep ultraviolet lithography. The best-case propagation losses of single-mode waveguides were <= 2.8 dB/cm and <= 1.9 dB/cm over continuous wavelength ranges of 466-550 nm and 552-648 nm, respectively. In-plane waveguide crossings and multimode interference power splitters are also demonstrated. Using this platform, we realize a proof-of-concept implantable neurophotonic probe for optogenetic stimulation of rodent brains. The probe has grating coupler emitters defined on a 4 mm long, 92 mu m thick shank and operates over a wide wavelength range of 430-645 nm covering the excitation spectra of multiple opsins and fluorophores used for brain stimulation and imaging. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement