Spatiotemporal optical solitons

TLDR

Spatiotemporal optical solitons are nondiffracting, nondispersing wavepackets that can exist, remain stable, and be generated in nonlinear optical media, with recent theory revealing self‑trapping pulses in one or two transverse dimensions and predictions of 2D/3D solitons in Bose–Einstein condensates using optical lattices. This article surveys recent experimental and theoretical advances in spatiotemporal optical solitons. Experiments have produced two‑dimensional solitons that suppress diffraction in one transverse direction in quadratic media, while theory predicts stable vorticity‑carrying solitons in competing nonlinearities, and the review highlights these successes, remaining challenges, and open questions.

Abstract

In the course of the past several years, a new level of understanding has been achieved about conditions for the existence, stability, and generation of spatiotemporal optical solitons, which are nondiffracting and nondispersing wavepackets propagating in nonlinear optical media. Experimentally, effectively two-dimensional (2D) spatiotemporal solitons that overcome diffraction in one transverse spatial dimension have been created in quadratic nonlinear media. With regard to the theory, fundamentally new features of light pulses that self-trap in one or two transverse spatial dimensions and do not spread out in time, when propagating in various optical media, were thoroughly investigated in models with various nonlinearities. Stable vorticity-carrying spatiotemporal solitons have been predicted too, in media with competing nonlinearities (quadratic–cubic or cubic–quintic). This article offers an up-to-date survey of experimental and theoretical results in this field. Both achievements and outstanding difficulties are reviewed, and open problems are highlighted. Also briefly described are recent predictions for stable 2D and 3D solitons in Bose–Einstein condensates supported by full or low-dimensional optical lattices.