Controlled Generation and Steering of Spatial Gap Solitons

Abstract

We demonstrate the first fully controlled generation of immobile and slow spatial gap solitons in nonlinear periodic systems with band-gap spectra, and observe the key features of gap solitons that distinguish them from discrete solitons, including a dynamical transformation of gap solitons due to nonlinear interband coupling. We also describe theoretically and confirm experimentally the effect of the anomalous steering of gap solitons in optically induced photonic lattices.

Self-trapping of optical vortices in waveguide lattices with a self-defocusing nonlinearity

“…Such discrete spatial solitons typically have their propagation constants residing in the semi-infinite gap (arising from the total internal reflection) or inside a true photonic band gap (arising from the Bragg reflection). Although gap solitons were traditionally considered as a temporal phenomenon in one-dimensional (1D) periodic media, spatial gap solitons in both 1D and 2D configurations have been demonstrated recently in a number of experiments with either a selffocusing or a self-defocusing nonlinearity [5,6,[9][10][11][12].…”

Dispersion control for matter waves and gap solitons in optical superlattices

“…This enables us to efficiently create a matter wavepacket with the correct internal structure at the relevant gap edge and avoid large time scales associated with the adiabatic acceleration. Such a wavepacket preparation technique was previously explored in optics [9,10,11,12,13]. Here we show that this method leads to more efficient soliton generation and shape control of the emerging gap solitons via dispersion control in the superlattice.…”

“…An alternative method for creating a wavepacket with the correct quasi-momentum and internal structure to produce spatial gap solitons was first suggested theoretically in the context of nonlinear optics [9,10,11], and was recently employed in experiments on weakly coupled waveguide arrays and optically-induced photonic lattices [12,13]. Applied to matter waves in optical lattices, this technique means that, instead of using a moving lattice to gradually drag a BEC wavepacket to the edge of the Brillouin zone, we start with two non-stationary wavepackets with opposite momenta (i.e.…”

Simple and efficient generation of gap solitons in Bose-Einstein condensates

“…For this lattice we define the recoil energy E recoil =h 2 (2π/λ) 2 /(2m). Such a lattice can be created by interfering two laser beams propagating at a small angle [9,16]. For the wavelength of 783 nm, used in Ref.…”