School of Science, Jiangnan University, Wuxi 214122, China.
Sensors (Basel). 2019 Jan 19;19(2):405. doi: 10.3390/s19020405.
In this paper, we derive the analytical expression for the sensitivity of grating-based surface plasmon resonance (SPR) sensors working in wavelength interrogation. The theoretical analysis shows that the sensitivity increases with increasing wavelength and is saturated beyond a certain wavelength for Au and Ag gratings, while it is almost constant for Al gratings in the wavelength range of 500 to 1000 nm. More importantly, the grating period (P) and the diffraction order (m) dominate the value of sensitivity. Higher sensitivity is possible for SPR sensors with a larger grating period and lower diffraction order. At long wavelengths, a simple expression of P/|m| can be used to estimate the sensor sensitivity. Moreover, we perform experimental measurements of the sensitivity of an SPR sensor based on an Al grating to confirm the theoretical calculations.
在本文中，我们推导出了基于光栅的表面等离子体共振（SPR）传感器在波长检测中的灵敏度的解析表达式。理论分析表明，灵敏度随波长的增加而增加，并在一定波长之后达到饱和，对于 Au 和 Ag 光栅而言，而对于 Al 光栅，在 500nm 至 1000nm 的波长范围内，灵敏度几乎保持不变。更重要的是，光栅周期（P）和衍射阶数（m）主导着灵敏度的值。具有较大光栅周期和较低衍射阶数的 SPR 传感器可以实现更高的灵敏度。在长波长下，可以使用 P/|m|的简单表达式来估计传感器的灵敏度。此外，我们还进行了基于 Al 光栅的 SPR 传感器灵敏度的实验测量，以验证理论计算。
