title: Terahertz bandwidth photonic Hilbert transformers based on synthesized planar Bragg grating fabrication.
abstract: Terahertz bandwidth photonic Hilbert transformers are proposed and experimentally demonstrated. The integrated device is fabricated via a direct UV grating writing technique in a silica-on-silicon platform. The photonic Hilbert transformer operates at bandwidths of up to 2 THz (~16 nm) in the telecom band, a 10-fold greater bandwidth than any previously reported experimental approaches. Achieving this performance requires detailed knowledge of the system transfer function of the direct UV grating writing technique; this allows improved linearity and yields terahertz bandwidth Bragg gratings with improved spectral quality. By incorporating a flat-top reflector and Hilbert grating with a waveguide coupler, an ultrawideband all-optical single-sideband filter is demonstrated.
authors.affiliation: Optoelectronics Research Centre, University of Southampton, Southampton, UK. Chaotan.Sima@soton.ac.uk
authors.forename: Chaotan
authors.initials: C
authors.lastname: Sima
authors.forename: J C
authors.initials: JC
authors.lastname: Gates
authors.forename: C
authors.initials: C
authors.lastname: Holmes
authors.forename: P L
authors.initials: PL
authors.lastname: Mennea
authors.forename: M N
authors.initials: MN
authors.lastname: Zervas
authors.forename: P G R
authors.initials: PG
authors.lastname: Smith