Decoupled Control of Mid‐Infrared and Near‐Infrared Light in a Hybrid VO 2 ‐Photonic Crystal Platform for Multifunctional Optical Applications

Multispectral modulation materials are crucial for managing electromagnetic waves and are highly desirable in the near‐infrared (NIR) and mid‐infrared (MIR) regions. However, achieving effective control of both bands in a single structure remains a major challenge. Here, we propose a multilayer structure with a VO 2 phase‐change layer and a 1D photonic crystal (PC) layer, capable of dynamic MIR switching and stable NIR high‐reflection protection. The device has an initial transmittance of up to 83% in the MIR range and drops to less than 1% after the phase change, with a relative modulation depth of 99%, satisfying the needs of various civil communication and detection systems. Meanwhile, it maintains a high reflectance of 80% around 1.06 µm both in the spectrum and under actual conditions for protection. The top PC layer can also generate tunable structural colors in the visible range, expanding the potential for environmental camouflage. To further favor switching performance in the MIR band, an infrared‐absorbing carbon nanotube (CNT) layer is placed on top, reducing the laser‐driven phase‐change threshold in the MIR band. This work provides a simple strategy for multispectral modulation without complex meta‐surfaces and sets a new example for smart optical limiting and LiDAR stealth.