To go into hiding on camouflage meta-surfaces

Inspired by the natural phenomena that rough sea surfaces often mask the ship target when the wind comes big, or another case in point, vehicles can usually hide themselves in the mountains with dense vegetation. Here in this paper, we demonstrate a practical strategy of hiding by using gradient-index meta-surfaces based on the quasi-conformal transformation optics. Different from the prevalent choice of the invisible cloak to virtually extinguish an object that is wrapped inside, our approach aims to suppress the detectability of the target through creating diffuse reflections by proposing the camouflage meta-surface underneath. Our design, possessing a flat and slim profile with solely a few randomly distributed dielectrics on a metallic sheet, can readily offer the perfect cover to mask the hiding object adjacently above in a broad frequency range.