A Double-Layer Structure SPR Sensor With Temperature Self-Compensation and Ultra-Wide Sensing Range for RI Detection

A surface plasmon resonance (SPR) sensor based on double-layer periodic array structure for ultra-wide refractive index (RI) sensing with temperature self-compensation is proposed and theoretically investigated. The temperature cross-sensitivity problem is solved by designing the double layers of ring and disk as different channels. The numerical results show that the proposed sensor exhibits an RI sensitivity of 1620 nm/RIU and a maximum temperature sensitivity of −0.65 nm/°C. Meanwhile, the effects of various structural parameters on the reflection spectra are also theoretically simulated and analyzed for adjusting and optimizing sensing performance. Furthermore, the sensor has the capability of detecting an analyte within the RI range from 1.2 to 1.6. The sensor proposed in the paper has a promising prospect for accurate detection of biomedical, organic chemical and drug delivery.