水脱附对微管谐振腔光学模式的影响.docVIP

  水脱附对微管谐振腔光学模式的影响# 钟健1,2，王娇1，黄高山1，袁国亮2，梅永丰1** （1. 复旦大学材料科学系，上海 200433； 5 10 15 20 25 30 35 40 2. 南京理工大学材料科学与工程学院，南京 210094） 摘要：本文利用薄膜自卷曲技术制备了 Y2O3/ZrO2 微管。在其上沉积氧化物薄膜过程中，观 察到了光学谐振模式的蓝移和红移。基于光谱分析的研究表明，该薄膜沉积过程中存在两种 相互竞争的因素在影响模式的移动，即：物理及化学吸附水的脱附和管壁厚度的增加。管壁 厚度增加相应提升了微管对光的限制作用，模式发生红移。另一方面，加热使得吸附水脱附 则使得模式蓝移。这两个因素的交互作用使模式发生双向移动的现象，同时，它们又都对光 学模式的品质因子有提升作用。这一发现说明此类微管谐振腔对周围环境的变化异常敏感， 有望在环境监测、湿度探测等领域有所应用。 关键词：Y2O3/ZrO2 微管；谐振模式；双向移动；脱附作用；品质因子；湿度探测 中图分类号：O436.1 Influence of water desorption on optical modes of microtube resonator ZHONG Jian1,2, WANG Jiao1, HUANG Gaoshan1, YUAN Guoliang2, MEI Yongfeng1 (1. Department of Materials Science, Fudan University, Shanghai 200433; 2. Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094) Abstract: Y2O3/ZrO2 microtube is fabricated by self-rolled technology, both blue- and redshifts of resonant modes are observed in the microtube resonator during a conformal oxide coating process. Investigation based on spectral analyses suggests that there are two competitive processes during coating: desorption of both chemically and physically absorbed water molecules and increase of the tube wall thickness. The redshift is due to the increase of the wall thickness and corresponding light confinement enhancement. On the other hand, desorption of water molecules by heating leads to a blueshift. The balance of these two factors produce the observed bi-directional shift of the modes while they both contribute to promote quality factors after coating. This work discloses the sensitivity of microtube resonators to surrounding change, and may find applications in environment monitoring or humidity detecting. Key words: Y2O3/ZrO2 microtube; resonant mode; bi-directional shift; desorption; quality factor; humidity detecting 0 引言 与其他形式的光学微腔相比，由纳米薄膜自卷曲形成的管状结构光学微腔呈现出很多独 特的性能和优点[1-4]。它们天然的中空结构易于被集成于芯片实验室（lab-on-chip）系统[5]。 在过去的几年里，自卷曲管状微腔已在很多领域得到应用，例如细胞培养装置[6,7]、微激光 器[8,9]、传感器[10]等等。尤其值得注意的是，这种自卷曲管状微腔具有（