Liquid crystal integrated metalens with tunable chromatic aberration

Zhixiong Shen, Shenghang Zhou, Xinan Li, Shijun Ge, Peng Chen, Wei Hu, Yanqing Lu
2020 Advanced Photonics  
Overcoming chromatic aberrations is a vital concern in imaging systems in order to facilitate fullcolor and hyperspectral imaging. By contrast, large dispersion holds opportunities for spectroscopy and tomography. Combining both functions into a single component will significantly enhance its versatility. A strategy is proposed to delicately integrate two lenses with a static resonant phase and a switchable geometric phase separately. The former is a metasurface lens with a linear phase
more » ... on. The latter is composed of liquid crystals (LCs) with space-variant orientations with a phase profile that is frequency independent. By this means, a broadband achromatic focusing from 0.9 to 1.4 THz is revealed. When a saturated bias is applied on LCs, the geometric phase modulation vanishes, leaving only the resonant phase of the metalens. Correspondingly, the device changes from achromatic to dispersive. Furthermore, a metadeflector with tunable dispersion is demonstrated to verify the universality of the proposed method. Our work may pave a way toward active metaoptics, promoting various imaging applications.
doi:10.1117/1.ap.2.3.036002 fatcat:7klnxjjlivbwvf3qvcgruuaqbi