Water-Resistant Subwavelength Perovskite Lasing from Transparent Silica-Based Nanocavity

Great research efforts are devoted to exploring the miniaturization of chip-scale coherent light sources possessing excellent lasing performance. Despite the indispensable role in Si photonics, SiO₂ is generally considered not contributing to the starting up and operation of integrated lasers. Here, this work demonstrates an extraordinary-performance subwavelength-scale perovskite vertical cavity laser with all-transparent SiO₂ cavity, whose cavity is ultra-simple and composed of only two parallel SiO₂ plates. By introducing a ligand-assisted thermally co-evaporation strategy, highly luminescent perovskite film with high reproducibility and excellent optical gain is grown directly on SiO₂ . Benefitting from their high-refractive-index contrast, low-threshold, high-quality factor, and single-mode lasing is achieved in subwavelength range of ≈120 nm, and verified by long-range coherence distance (115.6 µm) and high linear polarization degree (82%). More importantly, the subwavelength perovskite laser device could operate in water for 20 days without any observable degradation, exhibiting ultra-stable water-resistant performance. These findings would provide a simple but robust and reliable strategy for the miniaturized on-chip lasers compatible with Si photonics.