Recent advances in hybrid VO2/Si devices for enabling electro-optical functionalities

The change in the optical properties of VO2 across its insulator to metal to transition could give rise to novel photonic devices with beyond state-of-the art performance in terms of footprint, power consumption and speed operation. However, the final performance strongly depends on the control and efficiency of the phase transition in the VO2. For electro-optical applications, such control and efficiency is highly dependent on the electrode configuration. In this work, the influence of the electrodes is experimentally analyzed and an alternative approach is proposed to switch the VO2 to the metallic state by minimizing the electrical power consumption. The electro-optical performance of the proposed short-circuited electrode is also experimentally demonstrated. An extinction ratio of 12 dB is achieved with a 20μm long hybrid VO2/Si waveguide with an electrical power of only 11mW. The power consumption could be further reduced by decreasing the distance between the electrode and the silicon waveguide, which in this work has been fixed to 1.5μm, without affecting the optical losses.