Mid-infrared Fano resonance in heavily doped silicon and metallic nanostructures due to coupling of Wood-Rayleigh anomaly and surface plasmons

作者：Nguyen-Huu, N.^*; Cada, M.; Ma, Y.; Che, F.; Pistora, J.; Yasumoto, K.; Ma, Y.; Lin, J.; Maeda, H.

来源：Journal of Physics D: Applied Physics , 2017, 50(20): 205105.

DOI：10.1088/1361-6463/aa69aa

• Fano resonance
• Wood-Rayleigh anomaly
• surface plasmons
• highly doped Si
• grating structures
• numerical analysis
• bio/chemical sensors

This study reports the design and analysis of a plasmonic sensor based on a heavily doped silicon and metallic grating structure working in the mid-infrared region. The numerical results show that the reflection spectrum of the phosphorous-doped Si grating structure with a dopant concentration of 1 x 20(20) has a sharp asymmetric Fano resonance dip, which is strongly dependent on the refractive index change in the surroundings. It yields a sensitivity of 8000 nm/RIU (refractive index unit) and 950 nm/RIU working in the air and water media, respectively, very high values compared with that of existing devices. Moreover, the Fano resonance caused by coupling of the Wood-Rayleigh anomaly and surface plasmon resonances is demonstrated by calculating the magnetic field and Poynting vector patterns. Further, a feasible and easy fabrication process of the sensor featuring high performance is represented.

• 出版日期2017-5-24
• 单位南京林业大学; 哈尔滨工业大学