Description
We discuss novel types of subwavelength passive and active metadevices driven by resonances that allow generation of structured light and structural thermal radiation.
First, we demonstrate a new strategy for generation of optical vortices at the nanoscale that surpasses single-pixel phase control [1]. We reveal that interaction between neighbouring nanopillars of a meta-quadrumer can tailor both the intensity and phase of the transmitted light. Benefiting from the nanoscale footprint of the meta-quadrumers, we demonstrate high-density vortex beam arrays and high-dimensional information encryption.
Second, we employ the interplay between local (Mie resonances [2]) and nonlocal (bound states in the continuum) responses of dielectric resonant metasurfaces [3] to suggest a metalaser that can have any desired profile, including focal spots and lines, vector beams, and even holograms. The lasing mode is confined by nonlocal interaction between meta-atoms of a planar structure, and the beam wavefront is precisely shaped by locally varying dipole momenta. Notably, the scattered waves of the metalaser do not undergo resonant amplification like laser modes, being orders of magnitude weaker. As a consequence, the speckle noise becomes negligibly small in our metalaser holograms, providing a viable solution to the speckle noise problem of conventional laser holograms.
Finally, we employ a novel approach for thermal meta-emitters and demonstrate experimentally highly directional, rainbow free, vectorial-polarized thermal emission based on non-Hermitian metasurfaces. We employ topological charge engineering via the Brillouin zone folding that allows flexible triggering of vectorial polarization states being a previously unattainable capability of many thermal photonic systems. Experimental studies reveal doughnut-shaped narrowband thermal emission in the 3–5 μm atmospheric transparency window, exhibiting high spectral purity, extreme directionality and distinct vectorial polarizations.
References
[1] Y. Kivshar, Nano Letters 22, 3513 (2022).
[2] Q. Chen et al, Nature Nanotechnology 19, 1000 (2024).
[3] Y. Zeng et al, Nature 643, 12405 (2025).
| I am the presenting author | Yes |
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