Nearfield Vortex Dynamics of Supercell Bloch Modes

Abstract

Densely arranged optical vortices are natural solutions of high-symmetry Bloch modes in photonic crystals. However, strict symmetry constraints limit the potential spatial configurations of nearfield vortices, restricting the control over light-matter interaction. Here, we demonstrate a nearfield vortex dynamic within a supercell photonic crystal. By introducing paired rotations of triangular structures, we achieve high-quality-factor Bloch mode transition from evanescent valley modes, to quasi-bound states in the continuum, frustrated modes, and quasi-valleys. Each stage exhibits distinct nearfield vortex distributions, nonlinear overlap properties, and quality factors, revealing diverse physical behaviors for tailoring light-matter interaction. Notably, the asymmetric vortex configuration of frustrated modes enhances second harmonic generation, driven by an optimized nonlinear overlap factor. Our paired-rotation strategy offers a versatile design framework for creating supercell photonic crystals with unique nearfield vortex properties, presenting promising applications in lasing, nonlinear optics and optical forces.

30 pages, 17 figures

References in corpus (5)

• Observation of topological valley transport of sound in sonic crystals
• Observation of intrinsic chiral bound states in the continuum
• Valley Vortex States in Sonic Crystals
• All-optical polarization and amplitude modulation of second-harmonic generation in atomically thin semiconductors
• Efficient Second Harmonic Generation from Silicon Slotted Nanocubes with Bound States in the Continuum