Metasurface platform for simultaneous and uncorrelated emissivity control over MWIR and LWIR spectral bands

Thermal radiation in the mid-wave infrared (MWIR) and long-wave infrared (LWIR) underpins a wide range of imaging, sensing, and security technologies. While metasurfaces have enabled spectral and angular control of thermal emissivity, achieving spatially resolved and uncorrelated emissivity control across multiple infrared bands on a single platform remains a major challenge. Here we experimentally demonstrate a metasurface-based approach that enables pixel-level control of thermal emissivity in both the MWIR and LWIR bands simultaneously. The platform is based on a cavity-coupled metal-insulator-metal architecture supporting two infrared resonances whose spectral positions and strengths are orthogonally controlled through geometric design parameters. By systematically exploring the design space, we realize a broad emissivity palette and experimentally verify its thermal response using Fourier-transform infrared spectroscopy (FTIR) together with calibrated MWIR and LWIR thermal imaging. This capability allows the encoding of spatial thermal patterns that are either correlated or distinct in the two bands, enabling demonstrations of dual-band thermal camouflage and decoupled thermal image multiplexing on a single chip. The metasurface response is shown to be polarization-insensitive and robust over a wide range of temperatures and viewing angles. These results establish a scalable route toward multi-band, image-level control of thermal emission, with potential applications in thermal imaging, security, and infrared information encoding. (Figure presented.)