Band flips and bound-state transitions in leaky-mode photonic lattices

Abstract

Leaky-mode photonic lattices exhibit intricate resonance effects originating in quasi-guided lateral Bloch modes. Key spectral properties are associated with phase-matched modes at the second (leaky) stop band. One band edge mode suffers radiation loss generating leaky-mode resonance whereas the other band edge mode becomes a bound state in the continuum (BIC). Here, we present analytical and numerical results on the formation and properties of the leaky stop band. We show that the frequency of the leaky-mode resonance band edge, and correspondingly the BIC edge, is determined by superposition of Bragg processes chiefly generated by the first two Fourier harmonics of the spatial modulation. We derive conditions for the band closure and band flip wherein the leaky edge and the bound-state edge transit across the band gap. Our work elucidates fundamental aspects of periodic photonic films and has high relevance to the burgeoning field of metamaterials.

arXiv comment11 pages, 5 figures

References in corpus (6)

• Resonantly Trapped Bound State in the Continuum Laser
• Topological nature of bound states in the radiation continuum
• Spawning rings of exceptional points out of Dirac cones
• Analytical Perspective for Photonic Bound States in the Continuum in Photonic Crystal Slabs
• Anisotropy-induced photonic bound states in the continuum
• Bloch bound states in the radiation continuum in a periodic array of dielectric rods

Cited by in corpus (8)

• Topological photonic crystals: physics, designs and applications
• Unveiling the Enhancement of Spontaneous Emission at Exceptional Points
• Global $\mathbb{T}$ operator bounds on electromagnetic scattering: Upper bounds on far-field cross sections
• Exceptional points in lossy media enable decay-free wave propagation
• Metasurfaces with bound states in the continuum enabled by eliminating first Fourier harmonic component in lattice parameters
• Desktop laboratory of bound states in the continuum in metallic waveguide with dielectric cavities
• Analytical non-Hermitian description of Photonic Crystals with arbitrary Lateral and Transverse symmetry
• Bound states in the continuum accompanied by avoided crossings in leaky-mode photonic lattices