Efficient and Optically-Controlled Phase Modulator Based on VO2 EIT Structure

In this paper, we propose a dynamic EIT meta-surface to achieve large phase modulation of THz waves with low-loss. The dynamic EIT meta-surface is composed of a metallic coupled EIT meta-array and the embed vanadium dioxide components. By changing the state of VO2, the EIT resonant mode can be converted into a dipolar resonant. During this process, the transmitted frequency peak could be changed to a forbidden peak so that a 90-degree phase shift with low-loss at 0.6THz and 0.68THz frequency is obtained.