title: Bridging the gap between nanophotonic waveguide circuits and single mode optical fibers using diffractive grating structures.
abstract: In this paper, the use of diffractive grating structures to efficiently interface between a single mode fiber and a high index contrast waveguide circuit is outlined. We show that high index contrast grating structures allow for broadband and high efficiency coupling. Since no polished facet is required on the photonic integrated circuit to interface with the optical fiber, fiber-to-chip grating couplers enable wafer-scale testing, reducing the cost for testing large scale integrated optical circuits. We show that two-dimensional grating structures can solve the problem of the huge polarization dependence of high index contrast photonic integrated circuits. Finally, an optical probe is presented, which allows testing individual components of a photonic integrated circuit, analogous to the electrical probes used in micro-electronics.
authors.affiliation: Photonics Research Group, Ghent University/IMEC, Sint-Pietersnieuwstraat 41, B-9000 Ghent, Belgium.
authors.forename: G
authors.initials: G
authors.lastname: Roelkens
authors.forename: D
authors.initials: D
authors.lastname: Vermeulen
authors.forename: F
authors.initials: F
authors.lastname: Van Laere
authors.forename: S
authors.initials: S
authors.lastname: Selvaraja
authors.forename: S
authors.initials: S
authors.lastname: Scheerlinck
authors.forename: D
authors.initials: D
authors.lastname: Taillaert
authors.forename: W
authors.initials: W
authors.lastname: Bogaerts
authors.forename: P
authors.initials: P
authors.lastname: Dumon
authors.forename: D
authors.initials: D
authors.lastname: Van Thourhout
authors.forename: R
authors.initials: R
authors.lastname: Baets