title: Ultra-low loss photonic integrated circuit with membrane-type photonic crystal waveguides.
abstract: We report the design and testing of an SOI-based photonic integrated circuit containing two-dimensional membrane-type photonic crystal waveguides. The circuit comprises spot-size converters to efficiently couple light from a fiber into single-mode strip waveguides and butt-couplers to couple from strip waveguides to photonic crystal waveguides. Each optical interface was optimized to minimize back-reflections and reduce the Fabry-Perot noise. The transmission characteristics of each component are measured and record low propagation losses in photonic crystal waveguides of 24dB/cm are reported. The combination of an efficient two-stage coupling scheme and utilization of ultra-long (up to 2mm) photonic crystal waveguides reduces the uncertainty in determining the loss figure to 3dB/cm.
authors.forename: Sharee
authors.initials: S
authors.lastname: McNab
authors.forename: Nikolaj
authors.initials: N
authors.lastname: Moll
authors.forename: Yurii
authors.initials: Y
authors.lastname: Vlasov