Anisotropic confinement of chromophores induces second-order nonlinear optics in a nanoporous photonic metamaterial

Second-order nonlinear optics is the base for a large variety of devices aimed at active manipulation light. However, physical principles restrict its occurrence to non-centrosymmetric, anisotropic matter. This significantly limits number materials exhibiting optics. Here, we show that embedding chromophores in an array conical channels 13 nm across monolithic silica results mesoscopic matter and thus hybrid material showing second-harmonic generation (SHG). non-linear compared one achieved corona-poled polymer films containing identical chromophores. It originates confinement-induced orientational order elongated guest molecules nanochannels. leads non-centrosymmetric dipolar hence light-matter interaction on sub-wavelength, single-pore scale. Our study demonstrates advent large-scale, self-organised nanoporosity solids along with confinement-controllable scale provides reliable accessible tool design meta-optics.