Yan Hai, Huang Lijun, Xu Xiaochuan, Chakravarty Swapnajit, Tang Naimei, Tian Huiping, Chen Ray T
Opt Express. 2016 Dec 26;24(26):29724-29733. doi: 10.1364/OE.24.029724.
In this paper, unique surface sensing property and enhanced sensitivity in microring resonator biosensors based on subwavelength grating (SWG) waveguides are studied and demonstrated. The SWG structure consists of periodic silicon pillars in the propagation direction with a subwavelength period. Effective sensing region in the SWG microring resonator includes not only the top and side of the waveguide, but also the space between the silicon pillars on the light propagation path. It leads to greatly increased sensitivity and a unique surface sensing property in contrast to common evanescent wave sensors: the surface sensitivity remains constantly high as the surface layer thickness grows. Microring resonator biosensors based on both SWG waveguides and conventional strip waveguides were compared side by side in surface sensing experiment and the enhanced surface sensing capability in SWG based microring resonator biosensors was demonstrated.
本文研究并展示了基于亚波长光栅（SWG）波导的微环谐振器生物传感器独特的表面传感特性和增强的灵敏度。SWG结构由沿传播方向具有亚波长周期的周期性硅柱组成。SWG微环谐振器中的有效传感区域不仅包括波导的顶部和侧面，还包括光传播路径上硅柱之间的空间。与普通倏逝波传感器相比，这导致灵敏度大大提高和独特的表面传感特性：随着表面层厚度的增加，表面灵敏度始终保持较高。在表面传感实验中，对基于SWG波导和传统条形波导的微环谐振器生物传感器进行了并排比较，证明了基于SWG的微环谐振器生物传感器具有增强的表面传感能力。
