Laser Constructing Short-Range Disordered Metagratings for Visible Near-Infrared Polarization-Independent Absorption

摘要

Subwavelength-structured metasurfaces working in visible and near-infraredbands present a high challenge in large-scale device fabrication. In thisstudy, a scalable, high-efficient, and low-cost laser-induced nanopatterningtechnique is exploited to fabricate a kind of short-range disordered metagratings,which enables broadband polarization-independent absorption in thevisible to near-infrared wavelength. The short-range disorder of the laserinducednanogratings originates from the laser-induced thermal effect andcan be spontaneously organized during laser nanopatterning. The uniquedisorder can break the unidirectional characteristics of the nanogratings,which empowers the metagratings to excite coupled resonance modes. Thishelps to achieve near-perfect absorption in the visible to near-infrared band(400–1100 nm) with an excellent angular tolerance (up to 60°) and averageabsorptivities of 96.3% and 93.5% under the TM and TE modes, respectively.These low-cost metagratings can potentially inspire wide applications in thefields of solar cells, sensing, and thermal emitters.