Photonic crystals
From bands to radiation: how does periodicity select light?
An open periodic structure determines both which waves propagate and which modes radiate. The four papers here approach this through vortex conversion, thermal emission and spontaneous emission.
The common thread is dispersion and radiation channels in momentum space: retain high Q in one region, deliberately increase loss in another, or flatten dispersion. The relevant comparison spans the operating range, beyond a single resonance.
Start with the fundamentals
Periodic structures and bandgaps
Questions & mechanisms in the papers
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Cavity-assisted nonlocal metasurfaces for momentum-space broadband-operational optical vortice generation with maximum efficiency approaching 80%
Cavity-controlled coupling between BICs and degeneracy points connects quasi-flat-band design to vortex-conversion bandwidth and efficiency.
Structured coherent thermal emission from non-Hermitian metasurfaces
Brillouin-zone folding and mode coupling select emission angles, producing coherent thermal radiation with a polarization pattern.
Anomalous spontaneous emission enhancement by bound states in the continuum in nonlocal metasurfaces
Summing Bloch-mode contributions across momentum space tests the limits of a single-cavity high-Q intuition for emission.
High-Q resonance engineering in momentum space for highly coherent and rainbow-free thermal emission
Retaining high Q at Γ while lowering Q nearby selects thermal emission in both frequency and angle.