Two Hundred Nanometer Thin Multifocal Graphene Oxide Metalens for Varying Magnification Broadband Imaging

Conventional microscopes, which rely on multiple objective lenses for varying magnifications, are bulky, complex, and costly, making them difficult to integrate into compact devices. They require frequent manual adjustments, complicating the imaging process and increasing maintenance burdens. This paper explores the potential of single ultrathin graphene metalens to address this issue. We propose and demonstrate a 200 nm thin multiaxial focus graphene metalens with high-quality focusing, designed using spatial multiplexing and fabricated by one-step laser nanoprinting. A five-focal graphene metalens has been created, achieving clear imaging with varying magnifications across a broadband covering the entire visible wavelength. The graphene metalens has significantly reduced the size of the imaging system by orders of magnitude and holds profound potential for facilitating the integration and miniaturization of optical microscopic systems.