Soliton formation in a bound state in the continuum GaN waveguide polariton laser

TL;DR

This paper demonstrates the formation of bright solitons in a GaN waveguide polariton laser by exploiting bound states in the continuum, revealing new nonlinear phenomena in photonic systems.

Contribution

It reports the first observation of soliton formation in a polaritonic BIC state within a GaN waveguide laser, combining experimental evidence of BICs, lasing, and soliton dynamics.

Findings

Confirmation of symmetry-protected BICs via polarization vortex

Observation of polariton lasing from BIC states

Evidence of bright soliton formation above lasing threshold

Abstract

We study polaritonic bound states in the continuum (BIC) created in GaN waveguides. The existence of symmetry-protected BICs is confirmed by the suppression of light emission and the observation of a polarization vortex in momentum space. Upon increasing the pumping, polariton population accumulates at the BIC and we observe polariton lasing from the blueshifted BIC states. The assessment of the polariton BIC emission energy and of its momentum broadening as a function of pumping power, i.e. of polariton density, indicates the formation of a bright soliton above the lasing threshold. Soliton formation at the BIC is induced by the combination of negative mass BIC and of repulsive polariton-polariton interactions.