化学学报 ›› 2013, Vol. 71 ›› Issue (09): 1275-1280.DOI: 10.6023/A13040418 上一篇    下一篇

研究论文

纳米柱表面等离子体共振的调制及其红外光谱增强特性研究

吕江涛, 杨琳娟, 李志刚, 魏永涛, 张宝健, 梁丽勤, 王凤文, 司光远   

  1. 东北大学 信息科学与工程学院 沈阳 110819
  • 收稿日期:2013-04-17 出版日期:2013-09-14 发布日期:2013-06-13
  • 通讯作者: 司光远,E-mail:siguang0323@hotmail.com;Tel.:13603239536 E-mail:siguang0323@hotmail.com
  • 基金资助:

    项目受东北大学校内博士启动基金(XNB201302)、河北省自然科学基金(A2013501049)和中央高校基本科研业务费(N120323014)资助.

Resonance Tuning in Plasmonic Nanorods for Enhanced Infrared Spectrum Detecting

Lv Jiangtao, Yang Linjuan, Li Zhigang, Wei Yongtao, Zhang Baojian, Liang Liqin, Wang Fengwen, Si Guangyuan   

  1. College of Information Science and Engineering, Northeastern University, Shenyang 110819
  • Received:2013-04-17 Online:2013-09-14 Published:2013-06-13
  • Supported by:

    Project supported by the NEU Internal Funding (No. XNB201302), Natural Science Foundation of Hebei Province (No. A2013501049) and Fundamental Research Funds for the Central Universities (No. N120323014).

采用电子束直写光刻和离子束刻蚀的方法, 将具有不同周期的纳米金柱阵列制备于透明的石英衬底上. 通过对样品的透射光谱进行采集和分析可知, 改变纳米柱阵列周期可以实现在红外波段对局域表面等离子共振的精密调节. 实验结果表明, 在透射谱中共振谷的波长随着周期的增大而红移, 且红移的距离可以通过控制纳米柱阵列的周期进行调制. 理论模拟结果与实验结果在一定程度上相吻合. 此外, 还对不同高度的纳米柱阵列的透射谱进行比较和分析. 更进一步, 将制备的纳米银柱阵列和傅里叶变换光谱仪的ATR附件相耦合, 有效增强了葡萄糖溶液的吸收谱强度. 可见周期结构的纳米柱阵列可以有效增大样品表面的近场场强, 在信号传感和检测等领域有着广泛的应用前景.

关键词: 纳米柱, 表面等离子体共振, 调制, 傅里叶变换红外光谱仪, 光谱增强

Surface plasmons are electromagnetic waves propagating along metallic-dielectric interfaces and they have drawn considerable attention in the past ten years since extraordinary optical transmission (EOT) phenomenon was first reported. They can take different forms, from propagating waves to localized electron oscillations. Owning to their peculiar optical properties and particular capability of manipulating light at sub-wavelength scales, a wide range of practical applications have been enabled. Since the near-field of electromagnetic waves can be enhanced dramatically using plasmonic structures with different designs, surface plasmon based waveguides are of special importance to develop sensors and detectors with ultra-high sensitivity and figure of merit. Research on surface plasmons covers a broad scope with potential applications ranging from waveguiding to sensing. But plasmon assisted infrared detectors are rarely reported especially the ones working under near infrared (NIR) range. Tuning of surface plasmons in the NIR range is critical and essential to develop nanophotonic devices like modulators and sensors. Recently, plasmon assisted devices have drawn increasing interest. In this work, we show the combination of plasmonic nanorod arrays with NIR spectrum detection. Using electron-beam lithography (EBL) and ion milling techniques, gold (Au) nanorod arrays with varying periodicities were fabricated on transparent quartz substrates. By collecting and investigating the transmittance spectra of nanorods, precise tuning of localized surface plasmon resonance (LSPR) in the infrared range can be realized by changing the periodicity of nanorods. Experimental results show that the resonant wavelength of LSPR dips redshifts with increasing array periodicity and the distance of shift can be accurately controlled. Simulations show qualitative agreement with experimental results. The influence of waveguide sidewall on device performance is also discussed in detail. In addition, optical properties of nanorods with different heights were compared and investigated. By combining silver (Ag) nanorod structures with attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy technique, the absorbance of glucose can be effectively enhanced. Therefore, periodical nanorod arrays can significantly enhance the near field intensity, enabling extensive applications in signal sensing and detecting.

Key words: nanorods, surface plasmon resonance, tuning, FTIR, spectrum enhancement