Plasmonic Interference-Based Refractive Index Sensor Designed with Spectral Analysis and Structure Optimization

A nanoscale refractive index sensor based on plasmonic interference is proposed in this paper. The sensor has a rather simple and compact design, and the refractive index of materials under sensing can be retrieved from spectral shifting. Additionally, in order to pursue high accuracy and sensitivity in refractive index measurements, spectral analysis and structure optimization are adopted for sensor design. It indicates that the optimal sensor exhibits linear response to refractive index changes with a high sensitivity as ~1160 nm/refractive index unit. We believe the proposed design can be potentially applied for high-throughput measurements and rapid in-site detections.