title: Bi-photon spectral correlation measurements from a silicon nanowire in the quantum and classical regimes.
abstract: The growing requirement for photon pairs with specific spectral correlations in quantum optics experiments has created a demand for fast, high resolution and accurate source characterisation. A promising tool for such characterisation uses classical stimulated processes, in which an additional seed laser stimulates photon generation yielding much higher count rates, as recently demonstrated for a χ(2) integrated source in A. Eckstein et al. Laser Photon. Rev. 8, L76 (2014). In this work we extend these results to χ(3) integrated sources, directly measuring for the first time the relation between spectral correlation measurements via stimulated and spontaneous four wave mixing in an integrated optical waveguide, a silicon nanowire. We directly confirm the speed-up due to higher count rates and demonstrate that this allows additional resolution to be gained when compared to traditional coincidence measurements without any increase in measurement time. As the pump pulse duration can influence the degree of spectral correlation, all of our measurements are taken for two different pump pulse widths. This allows us to confirm that the classical stimulated process correctly captures the degree of spectral correlation regardless of pump pulse duration, and cements its place as an essential characterisation method for the development of future quantum integrated devices.
authors.affiliation: Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, New South Wales 2006, Australia.
authors.forename: Iman
authors.initials: I
authors.lastname: Jizan
authors.affiliation: CUDOS and MQ Photonics Research Centre, Department of Physics and Astronomy, Macquarie University, New South Wales 2109, Australia.
authors.forename: L G
authors.initials: LG
authors.lastname: Helt
authors.affiliation: Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, New South Wales 2006, Australia.
authors.forename: Chunle
authors.initials: C
authors.lastname: Xiong
authors.affiliation: Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, New South Wales 2006, Australia.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Collins
authors.affiliation: Laser Physics Centre, Australian National University, Canberra, Australian Capital Territory 2913, Australia.
authors.forename: Duk-Yong
authors.initials: DY
authors.lastname: Choi
authors.affiliation: NICTA-VRL, The University of Melbourne, Victoria 3010, Australia (now with Advanced Photonics Research Institute, GIST, Korea).
authors.forename: Chang
authors.initials: C
authors.lastname: Joon Chae
authors.affiliation: Dipartimento di Fisica, Universita degli Studi di Pavia, via Bassi 6, I-27100 Pavia, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Liscidini
authors.affiliation: CUDOS and MQ Photonics Research Centre, Department of Physics and Astronomy, Macquarie University, New South Wales 2109, Australia.
authors.forename: M J
authors.initials: MJ
authors.lastname: Steel
authors.affiliation: Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, New South Wales 2006, Australia.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Eggleton
authors.affiliation: Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, New South Wales 2006, Australia.
authors.forename: Alex S
authors.initials: AS
authors.lastname: Clark