Fully reconfigurable 2D active metasurface array

For the first time, we present an active 2D metasurface array and its demonstrated versatile beam steering. The array is composed of individually-addressable, gate-controlled 10×10 pixels where each pixel modulates the phase of light in reflection. Each pixel is a gated plasmonic nanoresonator with an indium tin oxide (ITO) layer embedded in its middle. When proper gate biases are applied to the array, the refractive index of the ITO layer changes, generating a phase gradient necessary for dynamic beam steering. By generating a reconfigurable binary phase grating, we have successfully demonstrated full-area, 2D arbitrary beam steering.