title: Design and demonstration of direct UV-written small angle X couplers in silica-on-silicon for broadband operation.
abstract: Experimental demonstration of small angle (0.8 degrees-5 degrees ) direct UV-written X couplers in silica-on-silicon is presented. Maximum and minimum coupling ratios of 95%(+/-0.8%) and 1.9% (+/-1%), respectively, were recorded. The structures also display very low polarization and wavelength dependence. A typical excess loss of 1.0 dB(+/-0.5 dB) was recorded. Device modeling using the beam propagation method and an analytical model showed good agreement with experimental results over a broad crossing angle and wavelength range.
authors.affiliation: Optoelectronics Research Centre, University of Southampton, SO17 1BJ Southampton, UK. mfra@orc.soton.ac.uk
authors.forename: Faisal R M
authors.initials: FR
authors.lastname: Adikan
authors.forename: Corin B E
authors.initials: CB
authors.lastname: Gawith
authors.forename: Peter G R
authors.initials: PG
authors.lastname: Smith
authors.forename: Ian J G
authors.initials: IJ
authors.lastname: Sparrow
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Emmerson
authors.forename: Christos
authors.initials: C
authors.lastname: Riziotis
authors.forename: Harith
authors.initials: H
authors.lastname: Ahmad