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 an ingenious all-solid, passive optical limiter via high-elastic-state thermo-compression, integrating indium phthalocyanine anchored to functional moieties within polymer microspheres. The key innovation lay in the coordination-bond anchoring strategy, which effectively suppressed indium phthalocyanine aggregation and facilitated the intersystem crossing. The resulting device demonstrated exceptional limiting performance, with a giant nonlinear absorption coefficient (4.80 × 10^-5 m/W) and an ultralow optical limiting threshold (< 0.013 J/cm²) at 532 nm, originating from long-lived triplet carrier accumulation. Moreover, the device exhibited excellent mechanical robustness and practical protection capability, as applied in smartphone camera. This work provided a viable strategy toward high-performance, practical organic solid optical limiter for next-generation laser protection applications.