title: Free-carrier-induced soliton fission unveiled by in situ measurements in nanophotonic waveguides.
abstract: Solitons are localized waves formed by a balance of focusing and defocusing effects. These nonlinear waves exist in diverse forms of matter yet exhibit similar properties including stability, periodic recurrence and particle-like trajectories. One important property is soliton fission, a process by which an energetic higher-order soliton breaks apart due to dispersive or nonlinear perturbations. Here we demonstrate through both experiment and theory that nonlinear photocarrier generation can induce soliton fission. Using near-field measurements, we directly observe the nonlinear spatial and temporal evolution of optical pulses in situ in a nanophotonic semiconductor waveguide. We develop an analytic formalism describing the free-carrier dispersion (FCD) perturbation and show the experiment exceeds the minimum threshold by an order of magnitude. We confirm these observations with a numerical nonlinear Schrödinger equation model. These results provide a fundamental explanation and physical scaling of optical pulse evolution in free-carrier media and could enable improved supercontinuum sources in gas based and integrated semiconductor waveguides.
authors.affiliation: Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Chad
authors.initials: C
authors.lastname: Husko
authors.affiliation: Center for Nanophotonics, FOM Institute AMOLF, Science Park 104, 1098 XG, Amsterdam, The Netherlands.
authors.forename: Matthias
authors.initials: M
authors.lastname: Wulf
authors.affiliation: Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Simon
authors.initials: S
authors.lastname: Lefrancois
authors.affiliation: Thales Research and Technology, 1 Avenue. A. Fresnel, 91767 Palaiseau, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Combrié
authors.affiliation: Thales Research and Technology, 1 Avenue. A. Fresnel, 91767 Palaiseau, France.
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Lehoucq
authors.affiliation: Thales Research and Technology, 1 Avenue. A. Fresnel, 91767 Palaiseau, France.
authors.forename: Alfredo
authors.initials: A
authors.lastname: De Rossi
authors.affiliation: Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Eggleton
authors.affiliation: Center for Nanophotonics, FOM Institute AMOLF, Science Park 104, 1098 XG, Amsterdam, The Netherlands.
authors.forename: L
authors.initials: L
authors.lastname: Kuipers