title: Design of optically path-length-matched, three-dimensional photonic circuits comprising uniquely routed waveguides.
abstract: A method for designing physically path-length-matched, three-dimensional photonic circuits is described. We focus specifically on the case in which all the waveguides are uniquely routed from the input to output-a problem that has not been addressed to date and that allows for the waveguides to be used in interferometric measurements. Circuit elements were fabricated via the femtosecond laser direct-write technique. We demonstrate via interferometric methods that the fabricated circuits were indeed optically path-length matched to within 45 μm, which is within the coherence length required for many applications.
authors.affiliation: Sydney Institute for Astronomy, School of Physics, University of Sydney, Australia. ccharles@physics.usyd.edu.au
authors.forename: Ned
authors.initials: N
authors.lastname: Charles
authors.forename: Nemanja
authors.initials: N
authors.lastname: Jovanovic
authors.forename: Simon
authors.initials: S
authors.lastname: Gross
authors.forename: Paul
authors.initials: P
authors.lastname: Stewart
authors.forename: Barnaby
authors.initials: B
authors.lastname: Norris
authors.forename: John
authors.initials: J
authors.lastname: O'Byrne
authors.forename: Jon S
authors.initials: JS
authors.lastname: Lawrence
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Withford
authors.forename: Peter G
authors.initials: PG
authors.lastname: Tuthill