基于银膜-石墨烯复合膜对称结构的SPR传感器研究

针对棱镜激励银膜SPR传感器灵敏度虽然较金膜结构高,但易被氧化、稳定性较差的缺点,提出一种棱镜耦合激励银膜－石墨烯－介质－石墨烯－银膜复合膜对称结构的SPR传感器,增加石墨烯膜层,解决银膜SPR传感器易氧化导致稳定性下降问题,采用角度调制的方法对SPR传感结构进行了性能参数分析,研究了金属材质、石墨烯以及检测介质的厚度对传感性能的影响。结果表明,银膜相比金膜,具有更好的共振效果,灵敏度较高,通过调节检测介质的厚度,可以改变角度的调节范围,实现了传感器的可调性,对称传感结构可以产生双共振峰SPR曲线,为分布式传感提供了可供参考的依据,石墨烯优化并提高了传感器的稳定性和检测灵敏度。     

金属包覆多层ATR 生物传感器的理论研究􀀂

利用衰减全反射(ATR)方法进行角度探测,通过改进传统传感器只用单层金属膜激发表面等离子波(SPR)进行探测的结构设计,利用金属包覆波导代替原来的单层的金属膜结构,并从理论上分析了和计算了金属包覆多层ATR生物传感器的检测机理,从而为研制高灵敏度、高解析力的ATR生物传感器提供了理论依据.     

表面等离子体共振传感器的仿真

为了得到基于相位检测、角度检测和波长检测的表面等离子体共振(SPR)生物传感器的高检测精度,利用Matlab建立了Kretschmann模型SPR传感器的数值仿真软件.系统地进行了棱镜折射率、测试介质折射率、金膜的厚度等因素对3种不同检测方式的SPR曲线的影响.理论分析结果表明:角度调制时与介质折射率增加时,SPR角也相应增加,相位检测对传感层的折射率具有选择性.     

SPR传感芯片的理论与实验研究

针对光纤SPR(表面等离子体共振)传感器制作工艺复杂的问题,提出了一种光纤先固定后部分镀膜的SPR传感芯片的制作方法.依据电磁场和射线理论,分析并讨论了此种波长调制部分镀膜SPR传感芯片的工作原理,采用MEMS制作工艺对探测光纤进行封装固定以后,再对光纤进行部分镀膜,其结构简单,工艺性好,易于实现批量化.最后,搭建了一套基、于波长检测的光纤SPR测试系统对其进行测试.实验结果表明:在折射率范围为1.33～1.36时,共振波长同折射率具有良好的线性关系,光谱仪分辨率为0.1 m时,其分辨率可达到3×10-5折射率单位.     

动态范围可调的波导型SPR传感器模型

表面等离子体共振 (SPR)技术是一种简单直接的传感技术 ,SPR对金属表面附近的折射率的变化极为敏感 ,利用这一性质 ,表面等离子体共振传感器已成为生物传感器研究领域的热点。现提出一种电光调制波导型SPR模型 ,模拟计算表明该模型在不损害灵敏度的条件下 ,扩大了探测的动态范围。     

基于Ⅰ型谐振结构的太赫兹超材料吸收体传感器研究

基于"Ⅰ"型谐振结构的太赫兹超材料吸波器可在0.523 THz处产生吸收率为99.5%,谐振峰半高宽为14 GHz,品质因数为37的极窄吸收峰,具有较强的频率选择性。在待测分析物厚度为8μm,折射率范围为1.0～1.8的情况下,该太赫兹超材料吸波器的折射率灵敏度为80.7 GHz/RIU,可作为高灵敏度的折射率传感器实现对待测分析物的检测。对谐振单元表面覆盖不同待测分析物情况下的电磁场分布进行仿真分析,揭示了折射率传感器的传感机理。此外,仿真研究了待测分析物厚度对该超材料吸收体传感器谐振频率及折射率灵敏度的影响。基于"Ⅰ"型谐振结构的太赫兹超材料吸波器具有结构简单、品质因数高、折射率灵敏度高等特点,在无标记的高灵敏度生物医学传感中具有潜在的应用前景。     

Love波传感器及其质量灵敏度测试

为实现流体领域的液相传感,设计并制作了基于36°-YX LiTaO3作为压电衬底、PMMA薄膜作为波导层的Love波传感器;通过微电流电铸实验测量得到Love波传感器的质量灵敏度为-2.281 g-1cm2.分析了波导层厚度、器件温度和电铸电极的厚度三个因素对灵敏度的影响,为进一步提高灵敏度提供了参考.     

基于I型谐振结构的太赫兹超材料吸收体传感器研究

基于“Ｉ”型谐振结构的太赫兹超材料吸波器可在0.523THz处产生吸收率为99.5%,谐振峰半高宽为14GHz,品质因数为37的极窄吸收峰,具有较强的频率选择性。在待测分析物厚度为8μｍ,折射率范围为1.0~ 1.8的情况下,该太赫兹超材料吸波器的折射率灵敏度为80.7GHz/RIU,可作为高灵敏度的折射率传感器实现对待测分析物的检测,对谐振单元表面覆盖不同待测分析物情况下的电磁场分布进行仿真分析,揭示了折射率传感器的传感机理。 此外,仿真研究了待测分析物厚度对该超材料吸收体传感器谐振频率及折射率灵敏度的影响。基于“Ｉ”型谐振结构的太赫兹超材料吸波器具有结构简单、品质 因数高、折射率灵敏度高等特点,在无标记的高灵敏度生物医学传感中具有潜在的应用前景。     

Si基微环谐振腔化学传感检测方法研究

提出了一种非标记光化学传感检测方法：光波导谐振谱检测,通过感应环形波导表面有效折射率变化进行化学传感;理论分析,并结合光学测试系统,利用此方法实现了微环谐振腔结构对NaCl离子、结晶紫分子溶液的在线浓度测量,实验得到：其检测灵敏度分别达181.47 pm/10－2,227 nm/（ mol·L－1）,证明了该方法可以应用于化学溶液检测领域。     

测量液体折射率与浓度的光纤光栅传感器

基于长周期光纤光栅的耦合模理论,从简化的三层光纤模型出发,研究了外界环境折射率变化时长周期光纤光栅传输谱的变化,并对氯化钠溶液的浓度和折射率进行了验证。实验结果发现,长周期光纤光栅的谐振波长与氯化钠浓度的变化近似成线性关系,而与折射率成二次曲线关系,这与数值模拟的结果一致。采用长周期光纤光栅测量液体的浓度和折射率的方法结构简单,且传感信号属于波长解调,避免了光强波动及光纤损耗的影响,整个传感系统全光纤化,能够实现对环境介质的在线、实时、快速、精确测量,还可用于特殊测量场合,实现远程遥测功能。     

Analysis and design of a novel radial folded waveguide structure for a feeder of a planar radial line antenna

Transmission characteristics of a new type of radial folded waveguide structure, consisting of a bifurcating metal disc with finite thickness between lower and upper radial waveguides and placed unsymmetrically in the folded portion as a general case, are investigated theoretically using a mode matching technique. A novel technique is proposed in which step junctions included in the bifurcating metal disc between lower and upper radial waveguides play an essential role in minimizing reflections caused by finite thickness of the bifurcating metal disc as well as the unsymmetry at the folded region and hence, a complete power transmission is achieved. Based on numerical computations some practical structure which is applied as a feeder for a planar radial line radiating structure of a plasma generating device is designed and perfect matching performance is demonstrated. ©1999 John Wiley & Sons, Inc. Int J RF and Microwave CAE 9: 415–423, 1999     

Numerical investigation for SPR-based optical fiber sensor

In the present work, a theoretical analysis of a surface plasmon resonance (SPR)-based optical fiber sensor is carried out. For the SPR-based optical fiber sensor with four-layer mode (fiber core/metal/sensing layer/sample), the effect of the thickness of metal layer and sensing layer on the spectrum of the transmitted power and wavelength has been studied. Based on the propagation wavevector till the first order expansion of the dispersion function, a detailed explanation for the relationships between the resonance wavelength with the thickness of the metal layer and sensing layer is presented.     

Calculation of a parallel-plate waveguide with a chiral insert by the mixed finite element method

A parallel-plate waveguide with metallic boundaries, containing an insert of a chiral substance, is considered. The field distribution inside the insert is studied when the system is excited by the guide’s normal wave incident on the insert. The problem is considered in the full vector formulation. The waveguide is calculated by the mixed finite element method, which makes it possible to avoid spurious modes (so-called spirits).     

开放磁路式磁致伸缩导波传感器原理的实验研究

磁致伸缩导波技术具有单点激励即可实现长距离检测的优点,但在检测非铁磁性构件或端部外露构件时面临难题.在分析已有磁致伸缩导波传感器检测原理的基础上,提出首先利用磁致伸缩效应在铁磁性波导管中产生导波;然后通过端部将其传入构件实现检测的原理,构建了开放磁路式磁致伸缩导波传感器原理的研究实验平台.采用270 kHz的纵向模态导波,在长2800 mm,壁厚2.5mm的Φ25 mm低碳钢钢管上可检测出0.5mm深刻槽和Φ5 mm的通孔缺陷,且在长2800 mm,壁厚2.5mm的Φ25mm不锈钢钢管上可得到明显的端部回波信号,从而为该传感器进一步应用于非铁磁性或端部外露构件检测提供了依据.     

Highly accurate and sensitive surface plasmon resonance sensor based on channel photonic crystal waveguides

A highly sensitive surface plasmon resonance (SPR) sensor based on channel photonic crystal waveguide (PCW) is proposed. The PCW is based on widely used lithographic and nano-fabrication compatible materials like TiO₂ and SiO₂. Gold has been used as a SPR active metal. By rigorously optimizing the different waveguide parameters, we have shown that there is significant transfer of modal power around phase-matching or resonance wavelength which has been utilized to design a compact and highly sensitive sensor for lab on chip. The ultra narrow width (∼765 pm for an interaction length of 10 mm) of surface plasmon resonance curve and sensitivity as high as 7500 nm-RIU⁻¹ will open a new window for bio-chemical sensing applications.     

基片式FBG在飞机蒙皮测试中的对称补偿研究

基片式FBG传感器封装结构在应变测试中受到广泛关注,尤其是在航空航天领域,其粘贴方式对监测飞机蒙皮应变具有重要意义。为了提高基片式封装结构的FBG测量飞机蒙皮应变精度,对薄板试验件粘贴基片式FBG传感器进行力学性能研究,实验结果表明传统粘结基片式FBG传感器方式会引起被测薄板材在拉伸过程中产生非线性变形。据此,通过ANSYS有限元分析软件仿真粘贴1 mm传感单元的1.5 mm薄板静态加载过程,并进行静力学有限元优化分析,力学分析及理论推导结果显示,对称粘贴基片式FBG传感单元能够解决应变与波长非线性关系,且能够有效补偿温度对测量的影响。搭建FBG解调系统与MTS力学测试实验系统,实验结果表明,在对称补偿的布点方式下,应变测试线性度为0.998,传感单元应变灵敏度为0.946 pm/με,提高了应变测试精度,可以有效的应用到飞机蒙皮应变测试。     

Optical parameters of calix[4]arene films and their response to volatile organic vapors

The Langmuir-Blodgett (LB) technique was employed to produce thin LB films using an amphiphilic calix-4-resorcinarene onto different substrates such as quartz, gold coated glass and quartz crystals. The characteristics of the calix LB films are assessed by UV-visible, quartz crystal microbalance (QCM) and surface plasmon resonance (SPR) measurements. UV-vis and QCM measurements indicated that this material deposited very well onto the solid substrates with a transfer ratio of >0.95. Using SPR data, the thickness and refractive index of this LB film are determined to be 1.14 nm/deposited layer and 1.6 respectively. The sensing application of calixarene LB films towards volatile organic vapors such as chloroform, benzene, toluene and ethanol vapors is studied by the SPR technique. The response of this LB film to saturated chloroform vapor is much larger than for the other vapors. The response is fast and fully recoverable. It can be proposed that this sensing material deposited onto gold coated glass substrates has a good sensitivity and selectivity for chloroform vapor. This material may also find potential applications in the development of room temperature organic vapor sensing devices.     

A surface wave exciter adapting to different‐diameter lines and its application to single power line communications

A surface wave exciter adapting to different‐diameter lines for single power line communications is proposed in this article. A side‐feeding structure is designed which enables surface wave communication on existing power lines without any damage. The proposed surface wave exciter is mainly composed of a horn, two symmetrical feeding structures, a separable feeding ring, and a separable short‐circuit metal ring. In order to avoid high order modes caused by insufficient excitation of side‐feeding structure, two‐port feeding structure is proposed. Meanwhile, the impedance matching of the exciter is improved. The exciter is designed to adapt to several lines with different diameters by using the separable feeding ring and short‐circuit metal ring. Two prototypes for the proposed design are fabricated and tested. The measured results indicated that the input reflection coefficients ( S₁₁ ) are less than ?10 dB and the efficiencies are better than 30% in the Sub‐6 GHz wireless communications. Moreover, a single power line communication system, which uses surface wave to transmit signal, is set up and tested. The transmission loss and the throughput are investigated to further prove the reliability of single power line surface wave communications.     

基于磁致伸缩位移传感器原理测量波导丝泊松比与线膨胀系数

波导丝是磁致伸缩位移传感器的核心元件,为快速测量波导丝泊松比与线膨胀系数,基于磁致伸缩位移传感器原理,提出了波导丝线膨胀系数与泊松比的测量方法。根据应力波传播特性以及应力波波速受温度影响的特性,构建了波导丝线膨胀系数、泊松比与波速的数学模型;利用传统的磁致伸缩位移传感器结构,测量了波导丝在25℃、50℃时的扭转波波速;设计了波导丝纵波激励结构,测量了波导丝中扭转波、纵波在传播距离相同时的传播时间;计算了波导丝线膨胀系数与泊松比。实验结果表明:实验中Fe-Ga波导丝的泊松比约为0.302,线膨胀系数约为18.70×10^-6/K。本文旨在深入探索波导丝弹性参数的新型快速测量方法,为传感器中波导丝的选型提供新思路。     

混合模匹配/矩量法分析介质负载波导缝隙天线

部分介质负载缝隙结构为天线性能的优化提供了额外的参数.利用模匹配与矩量法的混合方法分析了部分介质填充的矩形波导壁上的各类缝隙.将波导缝隙结构分为介质波导T型结和向半空间辐射的开路波导两个部分.用模匹配法分析T型结,矩量法分析开路波导.以缝隙上的模函数作为全域基函数,然后将T型结和开路波导进行级联从而得到缝隙结构的散射参数.利用混合方法对介质负载矩形波导上的横缝和纵缝计算得到了数值结果.与文献结果比较,验证了方法的正确性.方法避免了部分负载波导格林函数的复杂计算,从而有效地提高了分析效率.