Multi‐Wavelength Achromatic 3D Meta‐holography with Zoom Function

With the development of nanofabrication technology, meta-holography has shown unprecedented potential for light regulation. However, due to the wavelength mismatch, chromatic aberrations are inevitable in multi-wavelength meta-holography. Moreover, since the meta-hologram is difficult to refresh, zoom meta-holography has not been reported to date. Here, a multi-wavelength achromatic 3D meta-holography with a zoom function is developed, breaking through both the chromatic aberration interference and imaging limit for the first time. A wide-band 3D meta-hologram is generated and is used to design a wide-band metasurface fabricated with nanostructures based on the Pancharatnam-Berry phase, thus achieving the multi-wavelength meta-holography. A fast-tunable liquid lens with a large zoom range is designed, where a high elasticity polymer membrane and a high refractive index composite liquid with suitable viscosity and density are prepared to overcome the bottlenecks of limited zoom range and response speed. By jointly controlling the two liquid lenses, multi-wavelength achromatic 3D meta-holographic images with adjustable depth and size are successfully reconstructed. The zoom ratio of the meta-holographic images can reach 2.1, and the zoom response time can reach 5 ms. Such a tunable multi-wavelength achromatic 3D meta-holography has broad applications in storage, display, and information security.