Localized waves supported by the rotating waveguide array

TL;DR

This paper demonstrates that rotating waveguide arrays support unique linear localized modes due to effective potential and centrifugal effects, with stability analyzed in different media, contrasting nonrotating array behavior.

Contribution

It introduces the existence of linear localized modes in rotating waveguide arrays, a phenomenon not present in nonrotating arrays, and analyzes their stability in various media.

Findings

Localized modes exist in linear regime due to rotation.

Localization increases with rotation frequency.

Stable soliton families are identified in focusing and defocusing media.

Abstract

We show that truncated rotating square waveguide arrays support new types of localized modes that exist even in the linear case, in complete contrast to localized excitations in nonrotating arrays requiring nonlinearity for their existence and forming above the energy flow threshold. These new modes appear either around array center, since rotation leads to the emergence of the effective attractive potential with a minimum at the rotation axis, or in the array corners, in which case localization occurs due to competition between centrifugal force (in terms of quasi-particle analogy) and total internal reflection at the interface of the truncated array. The degree of localization of the central and corner modes mediated by rotation increases with rotation frequency. Stable rotating soliton families bifurcating from linear modes are analyzed in both focusing and defocusing media.