All-solid passive organic optical limiter via coordination-bond anchoring strategy

Organic optical limiters are vital for protecting human eyes and sensitive optics against laser radiation, offering exceptional optical properties, and ultrafast responses. However, their practical applications are hindered by aggregation-caused quenching and photodegradation in the solid state. Here, we proposed a novel all-solid, passive optical limiter via high-elastic-state thermo-compression, integrating indium phthalocyanine anchored to functional moieties within polymer microspheres. The key innovation lays in the coordination-bond anchoring strategy, which effectively suppressed indium phthalocyanine aggregation and dramatically enhanced its photophysical properties. Density functional theory calculations illustrated that such coordination bonding improved the intersystem crossing. The resulting device demonstrated exceptional limiting performance, with a giant nonlinear absorption coefficient ( β _eff  = 4.89 × 10 ^− 5 m/W) and an ultralow optical limiting threshold ( F _OL < 0.013 J/cm ² ) at 532 nm, originating from long-lived triplet carrier accumulation. Moreover, the device exhibited excellent mechanical robustness and practical laser protection capability, as applied in smartphone camera. This work provided presenting a viable strategy toward high-performance, practical organic solid optical limiter for next-generation laser protection applications.