Three-Dimensional Photoengraving of Monolithic, Multifaceted Metasurfaces

Metasurfaces present a potent platform to manipulate light by the spatial arrangement of sub-wavelength patterns with well-defined sizes and geometries, in thin films. Metasurfaces by definition are planar. However, it would be highly desirable to integrate metasurfaces with diverse, spatially programmed sub-wavelength features into a 3D monolith, to manipulate light within a compact 3D space. Here, a 3D photoengraving strategy is presented; that is, generation of such composite metasurfaces from a single microstructure via the irradiation of multiple interference laser beams onto different facets of the parent azopolymeric microstructure. Through photofluidization, this technique enables independent inscription and erasing of metasurfaces onto and from individual facets of 3D monoliths with arbitrary shapes and dimensions, in a high-throughput fashion (over approximately a few cm(2) at a time). By engraving discrete sub-wavelength 1D surface relief gratings of different pitches on different facets of an inverse pyramidal array, a multiplexing structure-color filter is demonstrated.

Automated summary

Metasurfaces are a powerful platform for manipulating light by arranging sub-wavelength patterns with defined sizes and geometries in thin films. Integrating metasurfaces with diverse, spatially programmed features into a 3D monolith to manipulate light within a compact 3D space is highly desirable. This can be achieved through a 3D photoengraving strategy, allowing for independent inscription and erasing of metasurfaces on individual facets of 3D monoliths with arbitrary shapes and dimensions.