Reflective chiral meta-holography:multiplexing holograms for circularly polarized waves

• 来源期刊: 光：科学与应用（英文版）
• 年，卷（期）: 2018,（4）
• 页码范围: 219-227
• 页数: 9页
• 语种: 英文
• DOI: 10.1038/s41377-018-0019-8

摘要

By allowing almost arbitrary distributions of amplitude and phase of electromagnetic waves to be generated by a layer of sub-wavelength-size unit cells,metasurfaces have given rise to the field of meta-holography.However,holography with circularly polarized waves remains complicated as the achiral building blocks of existing meta-holograms inevitably contribute to holographic images generated by both left-handed and right-handed waves.Here we demonstrate how planar chirality enables the fully independent realization of high-efficiency meta-holograms for one circular polarization or the other.Such circular-polarization-selective meta-holograms are based on chiral building blocks that reflect either left-handed or right-handed circularly polarized waves with an orientation-dependent phase.Using terahertz waves,we experimentally demonstrate that this allows the straightforward design of reflective phase meta-holograms,where the use of alternating structures of opposite handedness yields independent holographic images for circularly polarized waves of opposite handedness with negligible polarization cross-talk.