Wavelength-multiplexed metasurface for independent dual-channel continuous grayscale nanoprintings

Abstract

Metasurface that features flexible capability of light intensity modulation is widely applied to generate grayscale nanoprinting. To encode multiple grayscale nanoprintings into a single metasurface, different settings of analyzers are typically required. Here, a wavelength-multiplexed metasurface with no need of analyzer is proposed to realize a dual-channel continuous grayscale nanoprintings. The proposed metasurface is composed of two layers of nanobricks (NBs), where each layer of NBs independently acts as a polarizer under the light illumination at two selected wavelengths. By tailoring the orientation angles of NBs, distinct continuous grayscale nanoprintings with high fidelity and no crosstalk are encoded into two wavelength-dependent channels. Meanwhile, the proposed configuration can still generate the same high-quality nanoprintings with a large misalignment appearing between two layers of NBs, possessing outstanding structural robustness. The proposed wavelength-multiplexed strategy offers new insights into multi-channel display and paves the way for low-crosstalk display, high-density optical information storage and optical encryption.