Metasurface spatial filters for multiple harmonic signals

Abstract Nonlinear frequency mixings have shown an alternative way to create new electromagnetic sources in ranges that are difficult access with conventional techniques. To simultaneously use the fundamental pump beam and multiple harmonic signals generated same channel, a device capable of separating each component is required. Here, we propose experimentally demonstrate metasurface-based spatial filters for frequencies. The metasurface was designed using eight different split ring resonator-based phase elements 45° spacing, which allows wavefront shaping. one-dimensional gradient array produces cross-polarized reflection waves steering angles at third- fifth-harmonic frequencies (15 25 GHz) operates as metallic mirror 5 GHz. Our work suggests method enable simultaneous broadband multi-frequency based on nonlinear mixing.