Improved optical contrast of plasmonic phase change memory using a Fabry-Perot cavity.

As a promising technology to realize multilevel, non-volatile data storage and information processing, optical phase change technologies have 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. To the best of our knowledge, 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. Through the synergistic utilization of plasma and F-P cavity effects, an ultra-high switching contrast of around 70.6% is achieved. By varying the pulse power or duration, the proportion between the crystalline and amorphous states of the PCMs is altered, consequently modifying its refractive index. With its wide range of applications in optical storage and computing, the device holds significant potential for advancing these fields.