External cavity lasers based on wide-angle multifunctional metasurfaces

Metasurfaces are a promising platform to exceed their traditional counterparts not only in compactness but also for functionality. However, current designs are limited when trying to implement multiple, non-paraxial functions with a single metasurface as they are bound to either a small angular range or to low efficiencies. Here, we present a new non-local metasurface design that enables the implementation of multiple, independent functions with a large difference in deflection angle. We further demonstrate the capabilities of this approach for advanced control of light emission systems by creating a wavelength-tunable external cavity laser with holographic output based on such metasurface.