Rolled-Up Optical Microcavities with Subwavelength Wall Thicknesses for Enhanced Liquid Sensing Applications
Rolled-Up Optical Microcavities with Subwavelength Wall Thicknesses for Enhanced Liquid Sensing Applications
复制标题
DOI：
10.1021/nn100456r
复制
发表时间：
2010-06-01
期刊：
影响因子：
17.1
通讯作者：
Schmidt, Oliver G.
中科院分区：
文献类型：
--
作者：
Huang, Gaoshan;Quinones, Vladimir A. Bolanos;Schmidt, Oliver G.
通过从光刻胶牺牲层中释放预应力SiO/SiO(2)双层纳米膜，制作了由卷起的亚波长壁厚的环形谐振器构成的微管光学微腔。在卷起的纳米膜的光致发光光谱中观察到了回音廊模式，当在不同的周围液体中进行测量时，它们的谱峰位置发生了显著的移动，从而表明这些光流控微腔具有良好的传感功能。通过解析计算和有限差分的时间域模拟，数值研究了光学微腔中的光限制，并很好地描述了实验模式的移动。微管环形腔的最大灵敏度为425 nm/折射率单位，这是由于微腔的亚波长壁厚度设计导致了衰减场在周围介质中的显著传播所致。我们的光流控传感器在芯片实验室应用方面显示出很高的潜力，例如实时生物分析系统。
Microtubular optical microcavities from rolled-up ring resonators with subwavelength wall thicknesses have been fabricated by releasing prestressed SiO/SiO(2) bilayer nanomembranes from photoresist sacrificial layers. Whispering gallery modes are observed in the photoluminescence spectra from the rolled-up nanomembranes, and their spectral peak positions shift significantly when measurements are carried out in different surrounding liquids, thus indicating excellent sensing functionality of these optofluidic microcavities. Analytical calculations as well as finite-difference time-domain simulations are performed to investigate the light confinement in the optical microcavities numerically and to describe the experimental mode shifts very well. A maximum sensitivity of 425 nm/refractive index unit is achieved for the microtube ring resonators, which is caused by the pronounced propagation of the evanescent field in the surrounding media due to the subwavelength wall thickness design of the microcavity. Our optofluidic sensors show high potential for lab-on-a-chip applications, such as real-time bioanalytic systems.