共查询到20条相似文献,搜索用时 15 毫秒
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The paper deals with a fiber optic evanescent field absorption sensor that can be used for the detection of chlorine content in drinking water. The technique is based on the absorption of evanescent fields through the development of color owing to the reaction of an organic compound diethyl phenylene diamine with chlorine, which is already present in water. In the experiment, a U-shaped optical sensor probe is used because the sensitivity of the system improves due to the higher penetration depth achieved in this case. The improvement in sensitivity (in the case of U-shaped probed) is also shown experimentally. 相似文献
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Bernhard Lamprecht Elke Kraker Martin Sagmeister Stefan Köstler Nicole Galler Harald Ditlbacher Birgit Ungerböck Tobias Abel Torsten Mayr 《固体物理学:研究快报》2011,5(9):344-346
We present a novel optical sensor platform, combining monolithically integrated ring‐like sensor waveguides together with ring‐shaped thin‐film organic photodiodes (OPDs) on one substrate. The OPDs serve as integrated light detectors, simplifying the detection system by minimizing the number of required optical components. The waveguide structures, including a means of coupling light in and out of the waveguides, serve as sensing elements. The functionality of the concept is demonstrated by an integrated carbon dioxide sensor, utilizing absorbance as sensing principle. The integrated optical sensor platform is suitable for the parallel detection of multiple parameters in a single sensor chip using sensor arrays. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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EvanescentWavesandEnergyConservationCAOQing;DENGXiming(NationalLaboratoryonHighPowerLaserandPhysics,ShanghaiInstituteofOptics... 相似文献
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An evanescent field fibre-optic sensor for detecting chlorine in water is proposed and studied experimentally. The technique is based upon evanescent field absorption through the colour development of reacting diethyl phenylene diamine with chlorine, which forms an azo compound. Sensor systems with single and multi-fibre sensing elements were designed, constructed and evaluated for linearity of response, sensitivity, and reproducibility of results. The experimental results establish the feasibility of detecting low concentration chlorine in water using the proposed method. The results for an improved design are indicative of reasonably good reproducibility and linearity of the sensor response. 相似文献
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在共振情况下求解两能级原子在激光衰波场中的薛定谔方程,得到了基态原子反射率Rg、激发态原子反射率Re以及原子总反射率Rt的解析表达式。然后通过数值计算,详细讨论了Rg、Re,Rt与拉比频率,原子垂直于靶面方向运动的动能的依赖关系,得到一些有意义的结果。 相似文献
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D'Orazio A. Desario M. Giasi C. Mescia L. Petruzzelli V. Prudenzano F. 《Optical and Quantum Electronics》2004,36(6):507-526
A realistic design of evanescent field optical sensors, constituted by three different kinds of planar waveguides covered
by a sensing polymeric overlay, is performed. More precisely, the slab, the embedded strip and the ridge waveguides are considered.
The sensor operation is simulated, in both the cases of lossy guided and leaky mode propagation, via a home made computer code. The optimal waveguide transverse section and length are identified, the advantages and drawbacks
are shown. The ridge waveguide sensor exhibits appreciable characteristics: for a concentration C
w = 200 ppm of toluene in water, the absorbance pertaining to a device L = 2.6 cm long and for the guided quasi-TE00 mode is A ≅ 5, while it is A ≅ 0.054 for a device long L ≅ 24.1 μm and the leaky quasi-TE10 mode. The simulation results suggest that a selective excitation of the suitable propagation mode can enhance the sensor
performance. 相似文献
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Bernhard Lamprecht Tobias Abel Elke Kraker Anja Haase Christian Konrad Martin Tscherner Stefan Kstler Harald Ditlbacher Torsten Mayr 《固体物理学:研究快报》2010,4(7):157-159
We demonstrate a novel sensor type, which is based on the monolithic integration of luminescent optical sensor spots together with ring‐shaped thin‐film organic photodiodes on one substrate. The organic photodiodes serve as integrated fluorescence detectors, simplifying the detection system by minimizing the number of required optical components. The proposed concept enables filter‐less discrimination between excitation light and generated fluorescence light. The functionality of the concept is demonstrated by an integrated oxygen sensor, exhibiting excellent performance. The sensor spots are excited by an assembled organic light emitting diode. The integrated optical sensor platform is suitable for the parallel detection of multiple parameters. Sensor schemes for the analytical parameters carbon dioxide, temperature and ammonia, are proposed.
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Wave propagation through curved bends in integrated optical waveguides is governed by the evanescent field and the radiation loss of the eigenmodes. Since these parameters are influenced by the refractive index of the surrounding medium, circular bends in rib waveguides have been successfully employed as chemical sensors for liquids and gases. In this paper the electromagnetic field, the refractive index and the radiation loss of the eigenmodes are precisely determined by a fully vectorial approach based on the method of lines. An axial discretization and Bessel functions of complex order are employed for the rigorous computation of the evanescent field. The intensity distributions of the first modes in a rib waveguide are presented. The influence of the rib height on the sensitivity of the modal index to the refractive index of the surrounding medium is investigated. The results are useful for the optimization of the sensor design. 相似文献
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We report theoretical calculations and experimental data for guiding of polystyrene microspheres in the evanescent field of an optical waveguide. The waveguides used in our experiments were made using Cs+ ion-exchange in soda lime glass, which gives efficient trapping and high guiding velocities. The computations were done using a generalized version of Mie scattering theory, which gives good agreement with our experimental results. © 2005 The Optical Society of Japan 相似文献
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本文推导了双层声波导结构乐甫波传感器的频散方程和质量敏感度。首先,根据连续边界条件求解声波波动方程,并推导双层声波导结构下乐甫波传播的频散方程;然后根据微扰理论推导乐甫波传感器的质量敏感度。文中并最后给出基于ST-90°X石英基片的乐甫波传感器的算例分析。基片表面依次覆盖二氧化硅和金两层声波导,根据上述推导式子计算出乐甫波相速度及质量敏感度随着声波导层厚度变化的特性。结果表明:声波导层厚度增加时,乐甫波相速度减小,乐甫波模式增多,控制波导层厚度可以获得单一的乐甫波模式;选择波导层的厚度,乐甫波传感器可获得最大质量敏感度。 相似文献
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近年来,环境内分泌干扰物愈来愈受到人们的关注。对其用传统的检测技术分析,过程复杂、耗时长、价格昂贵,因此急需发展灵敏度高、反应迅速快、价格低廉的检测手段。介绍了一种平面波导型阵列倏逝波荧光生物传感器,在对系统光路参数进行模拟优化的基础上,可实现24个传感位点的同步、快速、灵敏检测。基于此阵列倏逝波荧光传感器,运用间接竞争免疫检测模式,优化并建立环境内分泌干扰物雌二醇的标准检测条件。实验结果表明,入射角在61.8°时,系统灵敏度最高。该方法对雌二醇检测线性检测区间为0.08~2.52 μg·L-1,检测限为0.05 μg·L-1,半抑制浓度为0.46 μg·L-1,完成单次样品的检测时间为20 min。利用该传感器对污水处理厂出水进行加标回收测试,回收率在84%~120%之间,相对标准偏差小于15%,表明该方法能够用于实际水体中雌二醇的快速检测。 相似文献
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We demonstrate how optical waveguides can serve as a high resolution illumination source to image hybrid nano-objects in near field optical microscopy. Nanohybrid particles deposited on the surface of glass waveguides are imaged in terms of topography, scattering and fluorescence. 相似文献
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提出了由十字连通形环形谐振腔耦合两个金属-介质-金属(metal-insulator-metal, MIM)波导的结构,并用有限元法数值研究了表面等离极化激元在结构中的传输特性.通过对透射谱的研究,系统地分析了MIM结构的传感特性.结果表明,在透射光谱中有三个共振峰,即存在三种共振模式,其中透射峰与材料的折射率呈线性关系.通过对结构参数的优化,得到了折射率灵敏度(S)高达1500 nm/RIU的理论值,相应的传感分辨率为1.33×10~(-4)RIU.更重要的是,灵敏度不受结构参数变化的影响,这意味着传感器的灵敏度不受制造偏差的影响.此外,谐振波长与环形腔中心半径成线性关系,该器件在较大波长范围内实现可调谐带通滤波.透射强度随着波导与环形腔间距的增大而减小,透射带宽同时减小,因此,可以通过控制环形腔与波导的耦合距离来调谐透射强度及透射带宽.研究结果对高灵敏度纳米级折射率传感器和带通滤波器的设计以及在生物传感器方面的应用都具有一定的指导意义. 相似文献
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Generation of sub-half-wavelength micro-optical traps by dichroic evanescent standing waves 下载免费PDF全文
The bi-dimensional optical lattices formed by several sets of laser
evanescent standing waves propagating at the surface of a dielectric
prism are investigated. The characteristics of the optical traps
including their depths and the sizes are analysed. It is shown that
the micro-optical lattice with a sub-half-wavelength size can be
achieved by the interference of the selected evanescent waves. The
scheme together with the recently developed atomic chip may be used
for atomic quantum manipulation. 相似文献