Kohandani Reza, Saini Simarjeet
Department of Electrical and Computer Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada.
Sci Rep. 2025 Mar 7;15(1):7960. doi: 10.1038/s41598-025-93102-5.
In this paper, a self-referencing evanescent field sensor based on surface plasmon resonances is designed and fabricated. The sensor is based on sub-wavelength two-dimensional gold gratings and is optimized to detect changes in the surrounding refractive index for a water-like material. The sensor has a dedicated mode for self-referencing, which is isolated from the surrounding environment and can be used to correct errors due to temperature variations. To understand the important design parameters and optimize the sensor for best performance, many variations were fabricated and measured experimentally. Using a localized surface plasmon resonance dominant mode, a high sensitivity of 435 nm/RIU was achieved experimentally, while the self-referencing mode was successfully isolated from the surrounding environment within a refractive index range of 1.34 to 1.39. Further, we show that by incorporating the self-referencing mode into the sensitivity measurements, the resolution of the sensor can be improved by a factor of 3.6. This approach can be employed effectively for resolution enhancement of the plasmonic sensors in the presence of environmental variations.
本文设计并制作了一种基于表面等离子体共振的自参考倏逝场传感器。该传感器基于亚波长二维金光栅，经过优化以检测类水材料周围折射率的变化。该传感器具有用于自参考的专用模式，该模式与周围环境隔离，可用于校正温度变化引起的误差。为了理解重要的设计参数并优化传感器以实现最佳性能，制作了许多变体并进行了实验测量。利用局域表面等离子体共振主导模式，实验实现了435 nm/RIU的高灵敏度，同时在1.34至1.39的折射率范围内成功将自参考模式与周围环境隔离。此外，我们表明，通过将自参考模式纳入灵敏度测量，传感器的分辨率可以提高3.6倍。在存在环境变化的情况下，这种方法可有效地用于提高等离子体传感器的分辨率。
