Ultra-high optical contrast of the plasmonic memory based on Fabry-Perot cavity and phase change materials

Phase-change photonic memory, as a promising technology to realize the tunability and non-volatility of optical storage and information processing systems, has attracted extensive attention in recent years. However, existing phase-change photonic devices face significant challenges such as limited switching contrast and high switching energy. This study introduces an innovative approach to tackle these issues by leveraging Fabry-Perot (F-P) cavity resonance and plasmon resonance techniques to enhance the modulation effect of phase change materials (PCMs) on the light. A novel device structure is proposed, featuring an elliptic nano-antenna placed on an F-P cavity waveguide composed of symmetric Bragg grating. This design exploits the enhanced electric field to achieve low power consumption and high contrast. The device enables crucial functions, including read, write, and erase operations, under all light conditions. Write and erase operations are accomplished using light pulses of 0.9 pJ and 3 pJ, respectively. Through the synergistic utilization of plasma and F-P cavity effects, an ultra-high switching contrast of 70.6% is achieved, revolutionizing the interaction pattern between light and PCM and establishing the device as the plasma device with the low power consumption and the large switching contrast. By modulating the multiple intermediate states of the phase change material, the device exhibits an outstanding accuracy of 96% in handwritten digit recognition using a three-layer perceptron. With its wide range of applications in optical storage and computing, the device holds significant potential for advancing these fields.