Programmable optical encryption using thickness-controlled stretchable chiral liquid crystal elastomers

The growing demand for cryptographic security encourages the innovation of advanced materials with unique optical properties to secure information using light. Structural colors with soft materials exhibit dynamically tunable optical properties in response to external stimuli, making them ideal for multi-level photonic encryption. However, most previous studies on structural color-based photonic encryption have predominantly focused on single-wavelength tuning while employing inadequate triggering methods for practical device applications. Here, we propose a chiral liquid crystal elastomer (CLCE) designed for stretching-induced multi-wavelength control to enhance photonic encryption functionality. By employing a heterogeneous configuration with thickness-modulated CLCE, we achieve multi-photonic band wavelength control under mechanical deformation. Furthermore, this method extends the tunable wavelength range beyond the visible spectrum into the infrared region and integrates a discrete multi-pixel array structure, enabling advanced spatial and spectral control for complex encryption schemes. This multi-wavelength modulation method is expected to provide significant potential for applications in photonic encryption, adaptive optics, and next-generation information security systems.