All-Dielectric Trifunctional Metasurface Capable of Independent Amplitude and Phase Modulation

It is essential to independently control the amplitude, phase, and polarization of electromagnetic waves, and there is an urgent need to integrate multiple functions independently on a single device. Here, an all-silicon multifunctional metasurface platform that can arbitrarily and independently encode three pairs of amplitude and phase profiles into a single-layer device is proposed. Three complex amplitude functions can be presented independently by switching the polarization states of the incident and transmitted waves. As a proof of the feasibility and flexibility of the platform, three examples are designed here: the first can generate multipair foci of equal intensity, the second can generate multipair axial bifocals of equal intensity, and the third can generate multipair foci of arbitrary intensity ratios. The experimental results are in good agreement with the simulations. The proposed multifunctional metasurface platform is powerful in manipulating the amplitude, phase, and polarization of electromagnetic waves, which can find applications in particle manipulation, biology, imaging, and other fields.