Multiplane Holographic Display by 3D-Printed Metasurface

Meta-optics represents a revolutionary advance in science and technology, enabling miniaturized and multifunctional optical systems through unprecedented subwavelength-level light control. Nanofabrication techniques such as electron beam and UV lithography are difficult to fabricate complex structures, but two-photon polymerization-based direct laser writing (TPP-DLW) can provide a fast, low-cost, mask-free method to create complex subwavelength metasurfaces. Here, the visible-light region holographic display metasurface is fabricated using this method. The multi-plane display complex amplitude hologram is optimized through the gradient descent method, and high-precision meta-atom processing with variable height is achieved through the optimization of the TPP process. The TPP-DLW method is extremely beneficial for studying and exploring the powerful high-degree-of-freedom light field control capabilities of meta-atoms. It is envisioned that the TPP-DLW method is expected to enable the rapid manufacturing of 3D metasurfaces or multilayer metasurfaces with large-area complex structures, which has great potential to promote disruptive changes in optical systems.