Zhou Jin, Liu Xiaoshan, Fu Guolan, Liu Guiqiang, Tang Peng, Yuan Wen, Zhan Xuefeng, Liu Zhengqi
Jiangxi Key Laboratory of Nanomaterials and Sensors, Provincial Key Laboratory of Optoelectronic and Telecommunication, College of Physics and Communication Electronics, Jiangxi Normal University, Nanchang 330022, Jiangxi, People's Republic of China.
Nanotechnology. 2020 Mar 25;31(28):285501. doi: 10.1088/1361-6528/ab8329.
Efficient optical sensing is desirable for a wide range of applications. For sensors, the spectral factors of the sensitivity (S) and the figure of merit (FoM) and the intensity change related figure of merit (FOM) are all the key factors in sensing measurement. In this work, we propose and demonstrate a novel high-performance plasmonic sensor platform using a resonant cavity array grating under oblique excitation. An ultra-sharp absorption mode with a bandwidth down to 1.3 nm is achieved when the oblique angle is 7.5°. During the sensing of the Na (Cl) ions in the solution, the spectral S and FoM factors reach 568 nm RIU (refractive index unit) and 436 nm RIU, respectively. The minimum detection limit is as low as 3.521 × 10 RIU. The FOM* factor is simultaneously up to 907. Moreover, the spectral intensity change is up to 57% when only a 1% concentration change is introduced into the solution. The detection limit of the concentration of the ions can be as low as 0.002%. The sensor has great potential applications due to its ultrahigh S, FoM, and FOM.
高效的光学传感对于广泛的应用来说是很有必要的。对于传感器而言，灵敏度（S）的光谱因子、品质因数（FoM）以及与强度变化相关的品质因数（FOM）都是传感测量中的关键因素。在这项工作中，我们提出并展示了一种新型的高性能等离子体传感器平台，该平台使用了在斜向激发下的谐振腔阵列光栅。当倾斜角度为7.5°时，可实现带宽低至1.3 nm的超尖锐吸收模式。在对溶液中的Na（Cl）离子进行传感时，光谱S因子和FoM因子分别达到568 nm/RIU（折射率单位）和436 nm/RIU。最低检测限低至3.521×10⁻⁶ RIU。FOM*因子同时高达907。此外，当溶液中仅引入1%的浓度变化时，光谱强度变化高达57%。离子浓度的检测限可低至0.002%。由于其超高的S、FoM和FOM，该传感器具有巨大的潜在应用价值。
