Dynamically controlled plasmonic nano-antenna phased array utilizing vanadium dioxide

We propose and analyze theoretically an approach for realizing a tunable optical phased-array antenna utilizing the properties of VO₂ for electronic beam steering applications in the near-IR spectral range. The device is based on a 1D array of slot nano-antennas engraved in a thin Au film grown over VO₂ layer. The tuning is obtained by inducing a temperature gradient over the device, which changes the refractive index of the VO₂, and hence modifies the phase response of the elements comprising the array, by producing a thermal gradient within the underlying PCM layer. Using a 10-element array, we show that an incident beam can be steered up to ± 22° with respect to the normal, by applying a gradient of less than 10°C.