Metasurfaces Can Sense Spatial Coherence of Light

Abstract

We report on a discovery that homogeneous metallic non-diffracting metasurfaces of a certain type respond differently to spatially coherent and incoherent light, enabling robust speckle-free discrimination between different degrees of coherence. The effect has no direct analogue in natural optical materials and may find applications in compact metadevices enhancing imaging, vision, detection, communication and metrology.