夏历副教授研究进展
夏历，1994-2004在清华园完成本科到博士阶段学习。2005-2009年在新加坡南洋理工大学从事博士后以及研究员工作。2010年至今，在华中科技大学光通信与光网络系刘德明教授团队工作。主要从事基于微纳结构光纤的表面等离子体共振传感技术和表面增强拉曼散射传感技术研究。
其中表面等离子体共振传感领域的一个研究热点是小型化多参量的传感器，我们首次利用光子晶体光纤的天然空气孔阵实现多通道多参量的表面等离子体传感，有效解决了多传感通道的制作和封装困难，该成果发表在权威期刊Optics Express （Vol. 19, No. 23, 2011）上。此外，我们还提出一种激光偏置入射的方法用于提升微结构光纤内的表面增强拉曼散射效率，该方法能明显改善光纤传感器的探测性能（如图1），研究结果将发表在2012年的Plasmonics上。
图1 在激光偏置入射和中心入射条件下，表面增强拉曼散射光纤传感器的浓度探测极限对比（样品为0.1M的罗丹明B溶液）
基于光子晶体光纤的表面等离子体共振传感领域的一个创新点是测量高折射率液体，我们首次设计出一种利用多芯光子晶体光纤的SPR折射率传感器（如图2），同时系统研究了该光纤中的模式耦合特性。他们研究发现，光纤的模式耦合特性显著地受到液体折射率变化的影响。随着液体折射率的增加，光纤基模与等离子体模式的耦合由不完全耦合过渡到完全耦合。该成果发表在权威期刊Optics Express （Vol. 20, No. 6, 2012）上。我们还提出一种本项目还提出一种由高折射率液体填充的空气孔作为纤芯的多芯光子晶体光纤SPR折射率传感器，并观察到了正负灵敏度共存的现象，这种新型结构的显著优点是可以在有限的光谱范围内测量较大折射率范围的待测样品。该研究成果即将发表在2012年Optics Express刊物上。
另外还从事基于微纳结构光纤传感技术研究。微纳结构光纤传感器制作工艺条件简单，峰值标定灵活，灵敏度高，用途广泛，已经成为光纤传感领域研究的热点。我们首次仅利用简单的熔接方法，制作了一种多用途MZI全光纤传感器（结构图如下图3所示）。该结构以细纤芯及包层光纤为传感头，利用一段多模光纤作为模式耦合器激发细光纤包层模式。由于倏逝场效应，外界环境的变化将导致细光纤包层和芯层传输模式间的相位差发生变化，从而引起干涉谱峰值发生漂移，可实现对外界液面、折射率、温度和轴向应力的测量，还值得关注的是首次提出了利用液面灵敏度大小同时实现对折射率高灵敏度测量的方法，该成果发表在权威期刊Optics Express （Vol. 20, No. 10, 2012）上。此外，我们还提出一种基于NCF-FBG结构的新型微结构光纤传感器，该结构传感器折射率灵敏度为目前报道的最高值，此外基于此结构传感器的研究，还可以利用多种测量方法实现对温度和折射率的同时检测，研究结果将发表在2012年的IEEE PTL上。
近三年发表的外文高质量期刊论文列表：（*为文章通讯作者）
1. Lecheng Li, Li Xia*, Yuanwu Wang, Yanli Ran, Chengliang Yang and DemingLiu, Novel NCF-FBG interferometer for simultaneous measurement of refractive index and temperature, IEEE Photonics Technology Letters, accepted, 2012.
2. Binbin Shuai, Li Xia* and Deming Liu, Coexistence of positive and negative refractive index sensitivity in the liquid-core photonic crystal fiber based plasmonic sensor, Optics Express, accepted, 2012.
3. Zhenhai Xie, Li Xia*, Lecheng Li and Deming Liu, A novel refractive index sensor based on microbend loss, Optik, accepted, 2012.
4. Zhenhai Xie, Li Xia* and Deming Liu, A novel sensor based on a dual-wavelength multilongitudinal modes fiber ring laser, Microwave and optical technology letters, accepted, 2012.
5. Yating Zhang, Derrick Yong, Xia Yu, Shuwen Zeng , Li Xia*, Deming Liu and Ying Zhang, Amplification of surface enhanced Raman scattering in photonic crystal fiber using offset launch method, plasmonics, published online already, 2012.
6. Lecheng Li, Li Xia*, Zhenhai Xie, Zhaolong Liao, FengTu and DemingLiu, Simultaneous measurement of refractive index and temperature using thinned fiber based Mach–Zehnder interferometer, Optics Communications, vol. 285, pp.3945-3949, 2012.
7. Lecheng Li, Li Xia*, Zhenhai Xie and Deming Liu, All-fiber Mach-Zehnder interferometers for sensing applications, Optics Express, vol. 20, no.10, pp. 11109-11120, 2012.
8. Lecheng Li，Li Xia*，Zhenhai Xie，Liangning Hao， Binbin Shuai and Deming Liu，In-line fiber Mach-Zehnder interferometer for simultaneous measurement of refractive index and temperature based on thinned fiber，Sensors and Actuators: A Physical, vol. 180, 19-24, 2012.
9. Binbin Shuai, Li Xia*, Yating Zhang, and Deming Liu, A multi-core holey fiber based plasmonic sensor with large detection range and high linearity, Optics Express, vol. 20, no.6, pp. 5974-5986, 2012.
10. Lecheng Li, Li Xia*, Zhenhai Xie, and Deming Liu, Numerical Analysis of the Three Co-directional Guided Modes in Optical Period Dielectric Waveguides Using Inverse Gaussian Apodization, European Physical Journal D, 66:94, 2012.
11. Chi Zhou, Yating Zhang, Li Xia*, and Deming Liu, Photonic crystal fiber sensor based on hybrid mechanisms: plasmonic and directional resonance coupling，Optics Communications, vol. 285, pp. 2466-2471, 2012.
12. Yating Zhang, Chi Zhou, Li Xia*, Xia Yu, and Deming Liu, Wagon wheel fiber based multichannel plasmonic sensor, Optics Express, vol. 19, no. 23, pp. 22863-22873, 2011.
13. Yating Zhang, Li Xia*, Chi Zhou, Xia Yu, Hairong Liu, Deming Liu, Ying Zhang，Microstructured fiber based plasmonic index sensor with optimized accuracy and calibration relation，Optics Communications, vol. 284, pp.4161-4166, 2011.
14. Yating Zhang, Chi Zhou, Li Xia*, Analyte-filled Fiber Core Assisted Surface Plasmon Sensing, Optical sensors and biophotonics II : Proceedings of SPIE :7990 , 2011.
15. Li Xia* , Binbin Shuai, Wei Li and Deming Liu, Polarization detection analysis of dual‐channel surface plasmon resonance sensing for silicone oils based on the D‐shaped fiber with a central hole, Optics Communications, vol. 285, 3730-3734, 2012.
16. Li Xia*, Binbin Shuai, Lecheng Li, Deming Liu, Analysis of coupling strength apodisation among the three co-directional guided modes in optical period dielectric waveguides, Optik, accepted, 2012.
17. Li Xia*, binbin Shuai, Wei Li, Deming Liu, “Simultaneous measurement of temperature and infinitesimal displacement using the high cladding mode coupling loss in fiber Bragg grating,” Sensors and Actuators: A. Physical, vol. 176, 53-56, 2012.
18. Li Xia*, Yating Zhang, Chi Zhou, binbin Shuai, Deming Liu, “Numerical Analysis of Plasmon Polarition Refractive Index Fiber Sensors with Hollow core and a Long Period Grating ,” Optics Communications ,vol. 284, 2835-2838, 2011.
