Double Axis Optical Beam Steering Using a Voltage Controlled Tunable Metasurface

The proposed tunable metasurface

Abstract

Tunable metasurfaces are planar structures capable of dynamic control on the wavefront of the reflected or transferred wave. Here, using transparent conducting oxides as a tunable material, a new functional structure is proposed to realize beam steering along two orthogonal axes in the near-IR regime. The phase of the reflected wave can be tuned by varying the electron carrier concentrations of the embedded transparent conducting oxide. This can be realized by adjusting the applied voltages to the pair of metal/insulator/transparent conducting oxide structures inside the proposed unit-cell. Two voltage modification plans are proposed corresponding to beam steering along the x and y axes. For both of them, detailed charge carrier concentrations and electromagnetic simulations are performed to determine the reflected wave characteristics of the unit-cell. It was found out that at the operational wavelength of λ=1.55µm, by adjusting the applied voltages in the 0 to 8 volts range, the phase of the reflected wave can be tuned in a span of 260° averagely for both plans. Finally, the capability of the proposed metasurface as a beam steering device has also been studied analytically. The proposed structure can be used in developing low-cost electrically steering Lidars.

Omid Abed
Omid Abed
Electrical Engineer

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