Fig. 20: On-chip metasurfaces and the applications.

a Schematic of the metasurface-VCSELs, depicting the standard VCSEL structure and the beam-shaping metasurface integrated at the backside of the substrate. b Schematics of the metasurface -VCSELs chip for wide-range dynamic beam steering applications. c Schematic of the metasurface integrated with a CMOS chip through physically 3D printed based on GD-TPN. d Photograph of the CMOS sensor with an array of 3 × 2 metasurfaces. Panels a and b are reproduced with permission²²¹. Copyright 2020, The Authors, published by Springer Nature. Panels c and d are reproduced with permission²²². Copyright 2021, The Authors, published by Springer Nature