Multi-plane vectorial holography based on a height tunable metasurface fabricated by femtosecond laser direct writing

Metasurfaces have prompted the transformation from the investigation of scalar holography to vectorial holography and led various applications in vectorial optical field manipulation. However, the majority of previously demonstrated methods focused on the reconstruction of a vectorial holographic image located at a predefined individual image plane. The evolution of polarization transformation during propagation can provide more design freedoms for realizing three-dimensional holography with complicated polarization feature. Here, we demonstrated a Jones matrix framework to generate vectorial holographic images with continuously varied polarization distributions at multiple different image planes based on a height tunable metasurface. The proposed metasurface is composed of IPL (a type of photoresist) nanofins with different lengths, widths, heights, as well as orientation angles fabricated by femtosecond laser direct writing. Such a fabrication method is in favor of 3D arbitrary structure processing, large area fabrication, as well as fabrication on curved substrates. Meanwhile, it is easy to fabricate structures that can be integrated with other devices, including optical fibers, photodetectors, and complementary metal–oxide semiconductors. Our demonstrated method provides a feasible way to generate high-dimensional vectorial fields with longitudinally varied features from the perspective of holography and can be used in the related areas including optical trapping, sensing, and imaging.