Janus Metasurface Hologram

The first metasurface hologram has been experimentally demonstrated to realize directionally asymmetric imaging for arbitrary polarization states in the visible spectrum. By leveraging TiO₂ meta-atoms that provide local and global rotation as well as width control, we achieve multifunctionality in a single-layer design—surpassing previous approaches based on spatial multiplexing or vertical stacking.

We report single-layer dielectric Janus metasurface holograms utilizing TiO₂ meta-atoms, each capable of simultaneously operating under forward and backward illumination, thereby overcoming limitations raised in earlier studies. By incorporating the Dammann grating principle and precise phase manipulation, our design produces high-fidelity holographic images for arbitrary polarized light at a wavelength of 532 nm. This approach not only simplifies fabrication and minimizes losses but also broadens the applicability of holography, paving the way for diverse innovations in compact and versatile optical technologies.

It is published in Advanced Optical Materials.

首個超穎介面全像影像已在實驗中被證明能實現針對任意偏振態的方向性不對稱成像。在設計中利用具備局部與全域旋轉以及寬度控制功能的二氧化鈦超穎原子，我們在單層結構中達到多功能性，超越了先前基於空間多工或垂直堆疊的方法。

我們提出單層介電質雅努斯超穎介面全像片，採用二氧化鈦超穎原子，每一單元皆可在正向與反向照明下同時運作，從而克服了先前研究中的限制。透過結合德曼光柵原理與精確的相位操控，我們的設計能夠在 532 nm 波長下，針對任意偏振光生成高保真度的全像影像。此方法不僅簡化了製程並降低了損耗，同時也拓展了全像技術的應用範疇，為緊湊且多功能的光學技術開創多元創新的可能性。