Enabling Access to the Confined Optical Field to Achieve High-Quality Plasmon Sensing

We predict a unique way to achieve high-quality plasmon sensing via enabling access to the originally confined optical field to efficiently interact with the surrounding medium. Refractive index sensing with high sensitivity (690 nm/RIU) and figure of merit (3391) is achieved in the optical region, which are twice larger than those of the original metal-insulator-metal structure. This sensing scheme is based on the purpose of making utmost use of the confined optical field to spatially overlap with the targets and, therefore, improving the sensing performance, which offers new perspectives for achieving high-sensitive chip-based plasmon sensors and integrated devices.