Broadband and polarization-independent complex amplitude modulation using a single layer dielectric metasurface

Abstract

Precise control over amplitude and phase across the entire space is crucial for generating user-defined wavefronts, which has significant value for designing flexible optical systems. Metasurfaces have emerged as compact and effective platforms for such control, offering high spatial resolution and continuity. However, traditional methods of control often impose constraints on the polarization state or operational bandwidth of the light source, the demonstration of comprehensive complex amplitude control in broadband and unpolarized light remains limited. In this study, we leverage the principle of dual meta-atoms interference to modulate amplitude and phase simultaneously using a single layer metasurface. Using randomly polarized illumination sources, nanoprinting and Fourier holography display of complex patterns are achieved within the wavelength range of 480-640 nm, the results are consistent with simulations. This approach presents several key advantages: continuous, precise and robust modulation of complex amplitude, polarization-independent and broadband response, which significantly reduces constraints on light source’s property and simplifies fabrication. This makes it well-suited for a variety of practical applications, including holographic displays, high-capacity communications, computational imaging, and laser beam processing.