Fig. 1. Schematic configuration of the proposed BDGA incorporating an MD, enabling an enhanced beam-steering efficiency in the longitudinal direction.

Fig. 2. (a) Configuration of the proposed BDGA and its operation that extends the beam-steering range. (b) Calculated spectral emission response with respect to the grating period for a 2D modeled BDGA for hBOX=4  μm.

Fig. 3. (a) Configuration of the proposed MD, comprising MS1 and MS2, facilitating the magnification of the beam-steering range. A meta-atom (or unit cell) and the highly confined magnetic field are also included. (b) Designed phase profile of the MD and (c) SEM images of the fabricated MS1 and MS2.

Fig. 4. (a) Experimental setup to inspect the performance of the prepared BDGA. (b) Captured intensity profiles of the wavelength-tuned main beam. (c) Observed emission angles corresponding to the main beam in terms of the wavelength.

Fig. 5. Measured emission efficiency of the main beam versus the wavelength.

Fig. 6. (a) Test setup to examine the beam deflection based on the MD with the incident angle. (b) Measured deflection angle and deflection efficiency. (c) Relative deflected beam power as a function of the incident angle.

Fig. 7. (a) Side and top views of the BDGA integrated with the MD. (b) Captured intensity profiles of the main beam radiated from BDGA without and with the MD. (c) Measured beam emission angle versus the wavelength. (d) Measured total efficiency of the main beam deflected by the MD versus the wavelength.