Zakaria Rozalina, Zainuddin Nur Aina'a Mardhiah, Raya Sofiah Athirah, Alwi Siti Anis Khairani, Anwar Toni, Sarlan Aliza, Ahmed Kawsar, Amiri Iraj Sadegh
Photonics Research Centre, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia.
Department of Computer and Information Science (DCIS), Faculty of Science and Information Technology (FSIT), Universiti Teknologi Petronas (UTP), Seri Iskandar 32610, Malaysia.
Micromachines (Basel). 2020 Jan 10;11(1):77. doi: 10.3390/mi11010077.
A single-mode optical fiber sensor uses surface plasmon resonance (SPR) with a bimetallic silver-copper (Ag-Cu) coating compared to a single layer of Ag and Cu itself. Bimetallic Ag-Cu sensors are constructed by simple fabrication on a side-polished optical fiber, followed by an electron beam evaporation of Ag and Cu films. For this investigation, the thickness of the single Ag layer was set to 30 nm and the single Cu layer was set to 30 nm; whereas for the bimetallic combined Ag-Cu layer the thickness of Ag was 7 nm and Cu 23 nm. The sensor performance was analyzed and compared experimentally and numerically using the COMSOL Multiphysics. A white light source was used with a broad optical bandwidth to provide a range of wavelengths to the optical fiber. The characteristics of the thin layers of Ag, Cu, and Ag-Cu as alcohol sensors were evaluated. We found that Cu was the most sensitive metallic layer compared to the Ag and the bimetallic Ag-Cu layers. For a 100% alcohol concentration, Cu showed a sensitivity of 425 nm/RIU followed by the bimetallic Ag-Cu layer with 108.33 nm/RIU, whereas the Ag layer was not detected. Interestingly, sensitivity reached saturation beyond the 20 nm thick layer of Ag. This shows that the Cu and the bimetallic Ag-Cu layers are suitable for an alcohol-based optical sensor.
与单层银（Ag）和铜（Cu）本身相比，单模光纤传感器采用了具有双金属银 - 铜（Ag - Cu）涂层的表面等离子体共振（SPR）技术。双金属Ag - Cu传感器通过在侧面抛光的光纤上进行简单制造，然后通过电子束蒸发Ag和Cu薄膜来构建。在本研究中，单Ag层的厚度设定为30 nm，单Cu层的厚度设定为30 nm；而对于双金属组合的Ag - Cu层，Ag的厚度为7 nm，Cu为23 nm。使用COMSOL Multiphysics对传感器性能进行了实验和数值分析与比较。使用具有宽光学带宽的白光源为光纤提供一系列波长。评估了Ag、Cu和Ag - Cu薄层作为酒精传感器的特性。我们发现，与Ag和双金属Ag - Cu层相比，Cu是最敏感的金属层。对于100%的酒精浓度，Cu的灵敏度为425 nm/RIU，其次是双金属Ag - Cu层，为108.33 nm/RIU，而Ag层未检测到灵敏度。有趣的是，当Ag层厚度超过20 nm时，灵敏度达到饱和。这表明Cu和双金属Ag - Cu层适用于基于酒精的光学传感器。
