Composite solitary vortices of three-wave mixing in quasi-phase-matched photonic crystals

TL;DR

This paper demonstrates the stable propagation of composite vortex solitons in 3D quasi-phase-matched photonic crystals with a checkerboard pattern, revealing new vortex mode interactions and stability properties.

Contribution

It introduces the concept of composite vortex solitons in 3D QPM-PhCs and explores their stability and mode interactions, which were not previously reported.

Findings

All solitons propagate stably for 10 cm in the crystal.

Vortex-doubling case remains stable over longer distances.

Multiple vortex modes including zero-vorticity, vortex, anti-vortex, and quadrupole are observed.

Abstract

We report the composite vortex solitons of three-wave mixing propagate stably in a three-dimensional (3D) quasi-phase-matched photonic crystals (QPM-PhC). The modulation of QPM-PhC is designed as a checkerboard pattern. The vortex solitons, composed by three waves ($\omega_{1,2,3}$) propagating through the lattices, exhibit a four-spotted discrete type, which gives rise to four distinct modes: zero-vorticity, vortex, anti-vortex, and quadrupole. The composite vortex solitons result from combinations of these modes and lead to four cases: vortex doubling, hidden vortices, vortex up-conversion, and anti-vortex up-conversion. Our findings indicate that all solitons can propagate stably through the crystals for 10 centimeters; however, only the vortex-doubling case remains stable over longer distances. This work enhances the understanding of vortex beam manipulation within 3D QPM-PhCs.