Collapse on the line -- how synthetic dimensions influence nonlinear effects

TL;DR

This paper demonstrates that synthetic dimensions enable wave collapse phenomena at milliwatt power levels in a one-dimensional fiber system, challenging the belief that such effects require higher dimensions.

Contribution

It introduces the concept of synthetic dimensions in fiber optics, showing collapse effects can occur in 1D systems with mixed interactions, unlike traditional 2D requirements.

Findings

Wave collapse observed at mW-power levels in 1D fiber loops.

Synthetic dimensions mimic 2D lattice behavior in 1D systems.

Collapse phenomena previously thought to need higher dimensions.

Abstract

Power induced wave collapse is one of the most fascinating phenomena in optics as it provides extremely high intensities, thus stimulating a range of nonlinear processes. For low power levels, propagation of beams in bulk media is dominated by diffraction, while above a certain threshold self-focusing is steadily enhanced by the action of a positive nonlinearity. An autocatalytic blow-up occurs, which is only stopped by saturation of the nonlinearity, material damage or the inherent medium discreteness. In the latter case, this leads to energy localization on a single site. It is commonly believed that for cubic nonlinearities, this intriguing effect requires at least two transverse dimensions to occur and is thus out of reach in fiber optics. Following the concept of synthetic dimensions, we demonstrate that mixing short and long-range interaction resembles a two-dimensional mesh lattice and features wave collapse at mW-power levels in a genuine 1D system formed by coupled fiber loops.