Wavelength-selective multifunctional light control with inverse designed dielectric metasurface

The metasurface has emerged as a powerful platform for achieving versatile and precise light control due to its extraordinary optical properties. However, multifunctional metasurface-based devices, usually employing shared apertures or cascading with different metasurfaces, suffer from inherent interference and complex configurations. Here, we propose a single-layer transmissive multifunctional metasurface performing distinct manipulations of light at specific wavelengths, free from inter-wavelength interference, benefiting from the strong dispersion of the silicon dielectric nanostructure. The metasurface is optimized using an adjoint-based inverse design with a gradient descent method. The simulated and experimental results confirm the successful integration of three functionalities within a single metasurface: beam stopper, linear polarizer, and half waveplate. The proposed multifunctional metasurface features an ultra-compact design with a simple configuration, which has the potential for applications in various fields, including photonic data transmission, hyperspectral imaging, and advanced optical sensing systems.