Manipulations of free‐space light are usually achieved through various metasurfaces and spatial light modulators. However, an external light source is required to excite these devices, making complete on‐chip integrations difficult. Integrated photonics enables the miniaturization and multi‐functionalization of optical systems by densely packing numerous optical components on a single chip. Particularly, plasmons have recently attracted extensive attention due to their unique abilities to enable the routing and manipulation of light at the nanoscale. Here optical wavefront shaping achieved by holographic metal‐insulator‐metal plasmonic gap waveguides is reported. An arbitrary free‐space wave's amplitude and phase information can be recorded in the waveguide by the amplitude variation of the guided wave. By elaborately designing the plasmonic gap waveguide, the guided waves can be molded into any desired free‐space light field, thus enabling complex free‐space functions including highly directional beams, dual beams with arbitrarily tailorable power ratio and radiation angles, focusing beams, and Airy beam generation. This study opens a new route for optical wavefront shaping via modulating guided waves. It paves the way for optical interconnects across multifunctional photonic integrated devices and free space, holding potential in optical communications, light detection and ranging, imaging, and displays.

A simple, planar, low-profile and wideband optical transparent end-fire magnetoelectric (ME) dipole antenna array is presented in this article. The metal mesh printing on the glass substrate uses a conductive silver grid layer. The top layer has electric and magnetic dipoles with the coplanar ground. An Γ-shaped transmission line is used to feed the ME dipole antenna and printed on the bottom layer. Good radiation performance of single antenna element, including an impedance bandwidth of 24.9%, average gain of 8 dBi, radiation efficiency of over 80%, and end-fire radiation patterns at 28 GHz band, are also achieved. Furthermore, a 1 Â 4 transparent end-fire ME-dipole antenna array is realized by employing the proposed ME-dipole single antenna element. A prototype was fabricated by in-house photolithography and lift-off process, which is measured to confirm the simulation results. Measured impedance bandwidth is 33% from 23.3 to 32.5 GHz (VSWR ≤ 2). End-fire radiation patterns are obtained across the entire bandwidth with a peak gain and radiation efficiency of 13.6 dBi and 80%, respectively. The optical transparency is around 66% across the visible spectrum.