Multichannel Wavelength-Selective All-Dielectric Metasurfaces Based on Complex Amplitude Modulation

The ability to independently manipulate the amplitude, phase, and polarization state of light constitutes a central problem in the advancement of integrated photonic devices. In this paper, we propose three multichannel wavelength-selective dielectric metasurfaces that utilize complex amplitude modulation to achieve precise and flexible simultaneous control over the spatial position, wavelength, and amplitude of multichannel optical fields. First, the designed metasurface simultaneously generates three pairs of independent foci with uniform intensity at wavelengths of 444 nm, 517 nm, and 700 nm, demonstrating foundational multi-wavelength control. Moreover, the second metasurface achieves complex amplitude distributions with different amplitude ratios through joint modulation of amplitude and phase, providing a solution for programmable adjustment of the relative intensity between foci, whereas the third metasurface offers high design freedom, capable of generating an arbitrary number of foci with customized positions and amplitude ratios across multiple wavelength bands, meeting the requirements for complex optical field construction. The findings suggest that such complex amplitude metasurfaces have broad application prospects in fields such as optical imaging, particle manipulation, and high-density information multiplexing.