title: Large-scale silicon nitride nanophotonic phased arrays at infrared and visible wavelengths.
abstract: We demonstrate passive large-scale nanophotonic phased arrays in a CMOS-compatible silicon photonic platform. Silicon nitride waveguides are used to allow for higher input power and lower phase variation compared to a silicon-based distribution network. A phased array at an infrared wavelength of 1550 nm is demonstrated with an ultra-large aperture size of 4  mm×4  mm, achieving a record small and near diffraction-limited spot size of 0.021°×0.021° with a side lobe suppression of 10 dB. A main beam power of 400 mW is observed. Using the same silicon nitride platform and phased array architecture, we also demonstrate, to the best of our knowledge, the first large-aperture visible nanophotonic phased array at 635 nm with an aperture size of 0.5  mm×0.5  mm and a spot size of 0.064°×0.074°.
authors.forename: Christopher V
authors.initials: CV
authors.lastname: Poulton
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Byrd
authors.forename: Manan
authors.initials: M
authors.lastname: Raval
authors.forename: Zhan
authors.initials: Z
authors.lastname: Su
authors.forename: Nanxi
authors.initials: N
authors.lastname: Li
authors.forename: Erman
authors.initials: E
authors.lastname: Timurdogan
authors.forename: Douglas
authors.initials: D
authors.lastname: Coolbaugh
authors.forename: Diedrik
authors.initials: D
authors.lastname: Vermeulen
authors.forename: Michael R
authors.initials: MR
authors.lastname: Watts