Figure 4.

Wide-angular-range and high-resolution beam steering by a metasurface-coupled phased array. (a) The comparison of steering range of a single SLM structure and a metasurface-coupled SLM structure. (left) without the metasurface, the SLM can provide only a small diffraction envelope. (right) With the metasurface-coupled SLM structure, since each scatterer is subwavelength, the steerable range can span from −90$°$ to +90$°$. (b) Illustration of the steering scheme (c) 1D far−field beam shapes at other steering angles. Red lines denote the theoretical shapes of the beams. Blue dots denote the measured data. (Reproduced from [29] with permission.)