On‐Chip Multidimensional Manipulations of Spatial Laser Fields by Jointly Controlling Amplitude and Phase of Metasurface

Abstract

Over the past decades, metasurfaces have experienced rapid development controlling the propagation of electromagnetic waves. Seamlessly combining metasurfaces with semiconductor devices enhance the device's performance and expand functional diversity. Currently, vertical‐cavity surface‐emitting lasers integrated with metasurfaces (MS‐VCSELs) employed to generate various wavefronts. However, the existing MS‐VCSELs that use only phase modulation still face limitations and challenges in generating customized fields, especially in 3D space. Here, amplitude‐phase metasurfaces are proposed and joint amplitude‐phase modulations are employed to increase the degree of freedom in controlling laser fields. By using electron beam lithography (EBL) and inductively coupled plasma reaction ion etching (ICP‐RIE), metasurfaces are directly fabricated on the back‐emitting surface of VCSELs, enabling samples to realize diverse functions such as multi‐focus multi‐plane generation and intensity control, multi‐plane holographic images, and laser beam deflections with different intensities. Compared to traditional discrete metasurface configurations, the proposed scheme achieves on‐chip integration of amplitude‐phase metasurface with the light source, enhancing the multidimensional laser field modulation capabilities of MS‐VCSELs in the 3D space while further promoting the cross‐integration of metasurfaces with optoelectronic devices. It is believed that MS‐VCSELs with amplitude‐phase modulations hold significant promise for applications in 3D imaging, facial recognition, and laser communications.