Fluid‐Induced Reconfigurable Polarization‐Insensitive Metasurfaces for Optical Wireless Communications

In optical wireless communication (OWC), the adaptability of infrared and visible spectra is attracting growing interest. These technologies are promising solutions for various real-world applications, including indoor, underwater, vehicular, and IoT systems. However, conventional OWC systems are constrained by their bulky structures and fixed optical properties, which limit their ability to provide on-demand communication services and integrate with on-chip technologies. Therefore, the demand for ultrathin, reconfigurable devices with real-time adaptability is becoming increasingly urgent to ensure efficient and reliable communication. Here, this study introduces a fluid-induced reconfigurable, polarization-insensitive metasurface to enhance the performance and flexibility of OWC networks. A key feature is its ability to adjust diffracted light to meet communication requirements, irrespective of the polarization state of the incident light. This metasurface utilizes infrared light at a wavelength of 1550 nm to enhance signal transmission and reduce environmental interference. In a proof-of-concept, a 0.5 mm × 0.5 mm metasurface is fabricated, and its focal length variation is verified in three different fluidic environments: Air (n = 1), Polymethyl methacrylate (PMMA) (n = 1.491), and AZ-GXR (n = 1.602). The proposed design offers reconfigurability, reduced polarization sensitivity, and consistent signal quality, making it ideal for next-generation OWC applications.