Lin Pao Tai, Giammarco James, Borodinov Nikolay, Savchak Mykhailo, Singh Vivek, Kimerling Lionel C, Tan Dawn T H, Richardson Kathleen A, Luzinov Igor, Agarwal Anu
†Materials Processing Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
§Photonics Devices and Systems Group, Singapore University of Technology and Design, Singapore 487372, Singapore.
ACS Appl Mater Interfaces. 2015 Jun 3;7(21):11189-94. doi: 10.1021/acsami.5b01013. Epub 2015 May 20.
A chip-scale mid-IR water sensor was developed using silicon nitride (SiN) waveguides coated with poly(glycidyl methacrylate) (PGMA). The label-free detection was conducted at λ=2.6-2.7 μm because this spectral region overlaps with the characteristic O-H stretch absorption while being transparent to PGMA and SiN. Through the design of a hybrid waveguide structure, we were able to tailor the mid-IR evanescent wave into the PGMA layer and the surrounding water and, consequently, to enhance the light-analyte interaction. A 7.6 times enhancement of sensitivity is experimentally demonstrated and explained by material integration engineering as well as waveguide mode analysis. Our sensor platform made by polymer-dielectric hybrids can be applied to other regions of the mid-IR spectrum to probe other analytes and can ultimately achieve a multispectral sensor on-a-chip.
利用涂覆有聚甲基丙烯酸缩水甘油酯（PGMA）的氮化硅（SiN）波导开发了一种芯片级中红外水传感器。无标记检测在λ = 2.6 - 2.7μm进行，因为该光谱区域与特征性的O - H伸缩吸收重叠，同时对PGMA和SiN透明。通过混合波导结构的设计，我们能够将中红外倏逝波调整到PGMA层和周围的水中，从而增强光与分析物的相互作用。实验证明灵敏度提高了7.6倍，并通过材料集成工程以及波导模式分析进行了解释。我们由聚合物 - 电介质混合体制成的传感器平台可应用于中红外光谱的其他区域以探测其他分析物，并最终实现片上多光谱传感器。
