Millisecond-level electrically switchable metalens for adaptive rotational depth mapping and diffraction-limited imaging
毫秒级电控可切换超透镜，用于自适应旋转深度映射和衍射极限成像
ミリ秒級電気スイッチング可能なメタルンスによる適応回転深度マッピングと回折制限イメージング
밀리초 수준의 전기적으로 전환 가능한 메탈렌즈를 이용한 적응형 회전 깊이 매핑 및 회절 한계 영상화
Lente metálica con conmutación eléctrica a nivel de milisegundos para mapeo adaptativo de profundidad rotacional y obtención de imágenes limitadas por difracción
Lentilles métalliques commutables électriquement en millisecondes pour la cartographie adaptative de profondeur de rotation et l'imagerie limitée par diffraction
Миллисекундный электрически переключаемый металенс для адаптивной вращательной картирования глубины и дифракционно-ограниченного изображения
Yeseul Kim ¹, Jihae Lee ², Won-Sik Kim ², Hyeonsu Heo ¹, Dongmin Jeon ¹, Beomha Yang ³, Xiaotong Li ¹, Harit Keawmuang ¹, Shiqi Hu ¹ ⁹, Young-Ki Kim ², Trevon Badloe ⁴ ⁵, Junsuk Rho ¹ ² ⁶ ⁷ ⁸
¹ Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
² Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
³ Department of Quantum Information Science, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
⁴ Department of Electronics and Information Engineering, Korea University, Sejong 30019, Republic of Korea
⁵ Division of Smart Energy Convergence Engineering, Korea University, Sejong 30019, Republic of Korea
⁶ Department of Electrical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
⁷ POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang 37673, Republic of Korea
⁸ National Institute of Nanomaterials Technology (NINT), Pohang 37673 Republic of Korea
⁹ Platform for Real-world Innovation in Smart Manufacturing and AI, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
We demonstrate an electrically tunable dual-mode metalens capable of polarization-sensitive focal control, combining high-resolution imaging and depth-sensing functionalities into a single compact device. By integrating hydrogenated amorphous silicon (a-Si:H) meta-atoms with a liquid crystal (LC) modulator, the proposed metasurface independently manipulates left- and right-circularly polarized (LCP/RCP) incident light, generating a rotating double-helix focal distribution for LCP and an extended depth-of-focus (DOF) for RCP illumination.
The meta-atoms were rigorously optimized using propagation and geometric phases, enabling precise phase control and high transmittance at a wavelength of 635 nm. Experimental characterization confirmed near-diffraction-limited lateral and axial resolutions, closely aligning with theoretical predictions. The integrated LC cell facilitates milliseconds polarizationswitching between depth-sensitive double-helix and high-resolution DOF imaging modes. We further verified depth-extraction capabilities by analyzing rotation angles from dual-image focal spots under mixed-polarization illumination.
Depth-resolved imaging of a rubber-tree leaf, a skeletal-muscle cross-section, and a live planarian retrieved color-coded depths, demonstrating the effectiveness on complex biological tissues. This polarization-driven, electrically tunable metalens thus provides a versatile and effective optical platform suitable for advanced applications in biomedical imaging, three-dimensional sensing, adaptive optics, and compact imaging systems.
