基于银膜孔阵列超强透射效应的相敏表面等离子体共振传感器的仿真研究

A high spatial resolution, phase-sensitive Surface Plasmon Resonance（SPR） sensor based on Extraordinary Optical Transmission （EOT） is proposed to monitor the binding of organic and biological molecules to the silver surface. The 2D nanohole-array configuration is well suited ~br dense integration in a sensor chip. The optical geomeWy is collinear, which simplifies the alignment with respect to the traditional Kretschmann arrangement for SPR sensing. Various design parameters of the device have been studied by simulation. The heterodyne technique is used to improve the sensitivity. The optimization results indicate that the sensor has the advantages of achieving high resolution and a wide dynamic range simuhaneously.     

Integrated Si‐based nanoplasmonic sensor with phase‐sensitive angular interrogation

This work is related to the development of an integrated Surface Plasmon Resonance (SPR) sensor on silicon platform. The optical properties of metallic nanogratings fabricated on the semiconductor structure allow direct plasmonic detection in transmission mode. Specially designed angular interrogation method provides a periodic signal with phase dependent on the conditions of surface plasmon excitation. Proposed technique leads to sensitivity better than 10^?6 RIU for conventional SPR Kretschmann configuration and was tested on the integrated Si‐based nanoplasmonic chip. Developed concept is promising for low‐cost mono and multi ‐sensing applications by portable or stationary platforms.     

LED based fiber optic surface plasmon resonance sensor

Modeling of a miniaturized fiber optic sensor based on surface plasmon resonance utilizing a broad band diffuse source is presented. Attenuated total internal reflection with Kretschmann configuration is the basis of the theoretical model. For simulation both meridional and skew rays are considered. The performance of the sensor is evaluated in terms of sensitivity, detection accuracy and signal to noise ratio. Effects of the numerical aperture of the fiber, core diameter and length of the sensing region on the performance parameters of the sensor are studied. The results are obtained for gold and silver metallic layer on the core of the fiber. The theoretical results obtained are compared with SPR based fiber optic sensor utilizing focused beam on the end face of the fiber from a collimated source. The advantages of using broadband LED (diffuse source) source for launching light in the fiber are the miniaturization, compactness and low cost of the sensor.     

契形结构光纤表面等离子体共振传感器研究

提出了一种契形端面结构的光纤表面等离子体共振(SPR)传感器激励模型. 采用时域有限差分法对契形SPR波导的共振模型进行数值模拟, 通过在光纤出射端抛磨契形角度并进行敏感膜修饰, 制出具有契形端面结构的类Kretschmann微棱镜式光纤SPR传感器, 实现激发SPR的光波调制.结果表明, 在1.3330–1.4215折射率范围内, 制备的契形光纤SPR传感器相对于常规光纤SPR传感器, 其平均灵敏度提高了近1–6倍, 1倍和6倍分别出现在小角度结构(15° 契形) 传感器和大角度结构(60°契形) 传感器, 且仍保持 10^-5 等级的分辨率. 该类型结构的传感器具有契形端面激励模式, 设计灵活性高、制备工艺简单、可微量检测样本等优点, 能够很好地适应于不同环境和测量条件的实际生化检测、环境监测需求. 关键词： 光纤传感器 表面等离子体共振 契形端面结构 折射率灵敏度     

基于银/二氧化钛复合膜的表面等离子共振气体传感器

表面等离子体共振是一种免标记的传感技术,当介质周围的介电常数发生改变时,则SPR谐振光谱特性也会随之改变.因此表面等离子体共振传感技术已广泛应用于生物化学和环境监测等领域.由于二氧化钛(TiO2)覆盖层不仅可以保护金属层,还能调谐SPR谐振的光谱强度和谐振波长于近红外波段,应用于1550 nm的光纤传感,其氧化还原反应...     

Surface plasmon optical sensor with enhanced sensitivity using top ZnO thin film

Surface plasmon resonance (SPR) is one of the most sensitive label-free detection methods and has been used in a wide range of chemical and biochemical sensing. Upon using a 200 nm top layer of dielectric film with a high value of the real part ε′ of the dielectric function, on top of an SPR sensor in the Kretschmann configuration, the sensitivity is improved. The refractive index effect of dielectric film on sensitivity is usually ignored. Dielectric films with different refractive indices were prepared by radio frequency magnetron (RF) sputtering and measured with spectroscopic ellipsometry (SE). The imaginary part ε′′ of the top nanolayer permittivity needs to be small enough in order to reduce the losses and get sharper dips. The stability of the sensor is also improved because the nanolayer is protecting the Ag film from interacting with the environment. The response curves of the Ag/ZnO chips were obtained by using SPR sensor. Theoretical analysis of the sensitivity of the SPR sensors with different ZnO film refractive indices is presented and studied. Both experimental and simulation results show that the Ag/ZnO films exhibit an enhanced SPR over the pure Ag film with a narrower full width at half maximum (FWHM). It shows that the top ZnO layer is effective in enhancing the surface plasmon resonance and thus its sensitivity.     

利用调谐滤波技术的光纤光栅复用传感器

采用光纤光栅悬臂梁线性调谐技术 ,提出了利用调谐滤波技术对光纤光栅复用传感信号进行检测的方案 ,在分析其基本工作原理的基础上 ,实验研究了其波分复用传感特性 ,传感测量的结果与光谱分析仪直接测量的结果基本一致。传感器的波长分辨率主要取决于系统的最小可探测光功率 ,由于采用了高灵敏度的光电测量系统 ,传感测量的波长分辨率可达 0 .0 0 5nm ,应变分辨率可达 5.7× 10 - 6 。     

基于多孔硅的表面等离子共振传感特性

提出了一种基于多孔硅的表面等离子共振传感模型:棱镜-金属膜-多孔硅薄膜-待测介质。在该结构中,多孔硅的折射率会随着样品浓度的变化而变化。利用有限元分析方法,数值模拟得到该结构的共振光谱,对模型进行了分析和参数优化。以乙二醇溶液为待测样本,对提出的传感结构的传感性能进行分析,得到该传感器对乙二醇的传感灵敏度约为267.85(°)/RIU,约为Kretschmann棱镜结构灵敏度的2.13倍。     

Sensor with increased sensitivity based on enhanced optical transmission in the infrared

Using enhanced optical transmission (EOT) through periodic nanoslits in thin metal films we demonstrate sensing in water with highly enhanced sensitivity in the infrared range for the first time. This is explained as a result of the enhancement in the penetration depth in the analyte thus increasing the interaction volume which in turn increases the sensitivity and allows for sensing of large bio-entities. The penetration depth enhancement in the EOT case is found to be larger than the corresponding enhancement factor in the Kretschmann configuration.     

热声转换的声表面波电压传感机制

提出了一种基于热声转换的高灵敏声表面波(SAW)电压传感机制并开展实验验证。从传热角度以及微扰理论出发建立了基于热声转换机制的SAW电压传感理论模型,探索了结构参数以及环境因素对SAW电压传感器灵敏度的影响规律。为了验证理论模型,在Y切石英基底上同芯片集成设计MEMS微型加热器与200 MHz声表面波器件以制备SAW电压传感器件,并搭建电压测试平台对传感器件开展性能测试。实验结果表明所制备的SAW传感器件电压与频率响应之间具有二次线性关系且在室温(20℃)下具有与理论相近的电压灵敏度(22.4 kHz/V),此外实验获得的环境温度对电压灵敏度的影响规律与理论相符。基于热声转换机制的SAW电压传感器能够显著的提高电压检测灵敏度。     

铝槽封装光纤光栅传感器的增敏特性研究

提出了一种光纤布喇格光栅的铝槽封装工艺,并对铝槽封装光纤光栅传感器的应变与温度传感特性进行了实验研究和理论分析.与裸光纤光栅的测试结果比较表明,铝槽封装工艺基本不改变光纤光栅应变传感的灵敏性,但是温度灵敏度系数提高了3.5倍.经过该工艺封装的光纤光栅可以探测识别0.2 με的应变与0.02℃的温度变化.     

Numerical and experimental investigation of temperature effects on the surface plasmon resonance sensor

The effects of temperature on a surface plasmon studied experimentally and theoretically. SPR resonance （SPR） sensor in Kretschmann configuration are experiments are carried out over a temperature range of 278- 313 K in steps of 5 K. A detailed theoretical model is provided to analyze the variation of performance with varying temperature of the sensing environment. The temperature dependence of the properties of the metal, dielectric, and analyte are studied, respectively. The numerical results indicate that the predictions of the theoretical model are well consistent with the experiment data.     

波长调制型表面等离子体共振的传感特性研究

表面等离子体共振(SPR)光学传感器能实现生物医学的快速、 无标记、 高精度检测,是生物化学分析的重要方法。 研制了基于波长调制型的Kretschmann结构表面等离子体共振(SPR)生物传感系统,研究了在体溶液传感方式下的传感性能。 利用不同浓度的乙醇和乙二醇溶液进行体溶液传感测试。 实验结果表明,在折射率低时共振波长对折射率变化响应的灵敏度低,但响应的线性度高;随着折射率增大,共振波长对折射率的响应变化的灵敏度提高。 在1.407 0～1.430 RIU折射率范围内,灵敏度高达11 487 nm·RIU-1。 传感器的共振波长的稳定性为0.213 8 nm,可分辨最小折射率趋近10-6 RIU。 所研制的波长调制型表面等离子共振传感器操作简单、 灵敏度高、 检测范围大,可实现浓度极低生物标记物的有效检测,在化学、 生物传感领域有重要的应用。     

Design of a highly sensitive photonic crystal waveguide platform for refractive index based biosensing

In this paper, a photonic crystal waveguide platform on silicon-on-insulator substrate is proposed in order to realize a highly sensitive refractive index based biosensor. Following the design, the analysis of the sensor structure are made by using the three dimensional Finite Difference Time Domain method. The principle of sensing is based on the change in refractive index, which in turn changes the output spectrum of the waveguide. Results show that the sensitivity of the sensor depends mainly on the geometrical properties of the defect region of the photonic crystal structure. The phenomenon is verified for various samples having refractive index ranging from 1 (air) to 1.57 (Bovine serum albumin). Further, the structure is compared with few other conventional photonic crystal waveguide designs to analyze the sensing performance. The estimated value of sensitivity of the sensor is found to be 260 nm/RIU with a detection limit of 0.001 RIU. This high sensitivity can enhance the performance of low-concentration analytes detection.     

Design of a compact photonic crystal sensor

The development of technology in photonic crystal (PC) structures has seen rapid progress. Using PCs in biosensing area may open new venues to achieve single molecule detection, and high resolution scanning. A novel PC sensor with improved performances, in terms of size, compactness and sensitivity is presented in this paper. The sensing element consists of dielectric cylinders with varying radius introduced along <01> and <10> directions of the crystal. The results show that the peak wavelength shifts to the high frequency region when only six cylinders are filled with analytes. Also, the peaks show a larger shift compared to the structure obtained using the entire PC waveguide as sensing region. The proposed sensor shows a better sensitivity to water than other analytes, where the peak wavelength tends to shift towards the low frequency region.     

High sensitivity dual core photonic crystal fiber sensor for simultaneous detection of two samples

The optical control ability of photonic crystal fiber (PCF) is a distinctive property suitable for improving sensing and plasma performance. This article proposes a dual-core D-channel PCF sensor that can detect two samples simultaneously, which effectively solves the problems of coating difficulty and low wavelength sensitivity. The PCF has four layers of air holes, which dramatically reduces the optical fiber loss and is more conducive to the application of sensors in actual production. In addition, by introducing dual cores on the upper and lower sides of the central air hole, reducing the spacing between the core and the gold nanolayer, a stronger evanescent field can be generated in the cladding air hole. The optical fiber sensor can detect the refractive index of two samples simultaneously with a maximum sensitivity of 21300 nm/RIU. To the best of our knowledge, the sensitivity achieved in this work is the highest sensitivity with the dual sample synchronous detection sensors. The detection range of the refraction index is 1.35-1.41, and the resolution of the sensor is 4.695×10^-6. Overall, the sensor will be suitable for medical detection, organic chemical sensing, analyte detection, and other fields.     

A novel temperature and strain sensing method based on high-birefringence fiber loop mirror

A novel temperature and strain sensor based on a fiber loop mirror (FLM) consisting of high-birefringence polarization-maintaining fibers is proposed. The output spectrum was theoretically deduced based on Jones matrix. Two equal-length high-birefringence fibers (HBFs) with different birefringence indices were inserted into the FLM. The temperature and strain sensing system was built. The sensitivity coefficients of temperature and strain were calibrated respectively. The double parameters measurement of temperature and strain was realized. High resolution of 2.38 μ? has been achieved for strain sensing. Meanwhile, the temperature resolution is 0.016 °C.     

铜片封装光纤光栅传感器的应变和温度传感特性研究

提出了一种光纤光栅的铜片封装工艺，并通过实验和理论分析研究了光纤光栅的应变和温度传感特性.与裸光纤光栅的测试结果相比，铜片封装工艺基本不改变光纤光栅应变传感的灵敏度，但是温度灵敏度系数提高了2.78倍.经过铜片封装后的光纤光栅可以探测到的应变和温度分别为1 με和0.03℃，便于工程应用.     

Temperature Effects on Prism-Based Surface Plasmon Resonance Sensor

We theoretically analyse the temperature effects on a surface plasmon resonance （SPR） sensor in Kretschmann configuration. The temperature effects include the thermo-optic effect and the dispersion of thermal-optic coefficient in the dielectric along with the thermal expansion effect, phonon-electron scattering and electron-electron scattering in the metal layer. We simulate the temperature dependence of the resonance position and the sensitivity of the SPR sensor under wavelength-interrogation and angular-interrogation mode of operation and the differences are pointed out in the two modes.     

A fiber-optic voltage sensor based on macrobending structure

We propose and demonstrate an optical voltage sensing scheme based on a macrobending optical fiber in a ratiometric power measurement system. This novel approach to sensing has not been utilized before and has the advantage that the sensor involves simple fabrication compared to existing fiber-optic voltage sensors. To prove the feasibility of such a fiber-optic sensor, a sensor for a voltage range from 0∼100 V is demonstrated, with a resolution of 0.5 V. The sensor is robust, linear, and shows a competitive measurement resolution. The sensor can be easily scaled to suit other voltage levels and be effectively combined with optical current sensors.