Geometry-Programmable Perovskite Microlaser Patterns for Two-Dimensional Optical Encryption.

Lasing signals with easily distinguishable readout and cavity-geometry-dependent output are emerging as novel cryptographic primitives for two-dimensional (2D) optical encryption, while their practical application is restricted by the challenge of integrating different lasing elements onto an identical 2D pattern. Herein, a lithographic template-confined crystallization approach was proposed to prepare large-scale perovskite microstructures with any desired geometries and locations, which enabled them to serve as 2D lasing patterns for reliable encryption and authentication. These prepatterned perovskite microstructures realized whispering-gallery-mode lasing and also demonstrated outstanding reproducibility of lasing actions. Benefiting from the feature of their cavity-geometry-dependent lasing thresholds, we achieved controllable laser output from different shaped elements, which was further utilized for the proof-of-concept demonstration of a cryptographic implementation. The remarkable lasing performance and feasible preparation of 2D microlaser patterns with customized geometries and locations provide us deep insights into the concepts and fabrication technologies for 2D optical encryption.