title: Realization of efficient metal grating couplers for membrane-based integrated photonics.
abstract: Grating couplers are widely used to couple light between photonic integrated circuits and optical fibers. Here, we fabricate and characterize a device based on a buried metal grating. In contrast to dielectric gratings, simulations predict strongly reduced parasitic leakage of light to the substrate and are performance independent of the optical buffer thickness, while using standard fabrication processes with high yield. The gratings show a 3 dB bandwidth of 61 nm and chip-to-fiber coupling efficiency of 54%, which makes them attractive building blocks for on-wafer testing and dense optical interconnects.
authors.forename: Aura
authors.initials: A
authors.lastname: Higuera-Rodriguez
authors.forename: Victor
authors.initials: V
authors.lastname: Dolores-Calzadilla
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Jiao
authors.forename: Erik J
authors.initials: EJ
authors.lastname: Geluk
authors.forename: Dominik
authors.initials: D
authors.lastname: Heiss
authors.forename: Meint K
authors.initials: MK
authors.lastname: Smit