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通过测量基于聚二甲基硅氧烷(PDMS)基片的液芯柱透镜的后焦距,可实现液体折射率的快速测量;根据液体质量分数与折射率之间的良好线性关系,准确计算出待测透明液体的质量分数.搭建光学测量系统,以NaCl溶液和蔗糖溶液为例,构建了液体质量分数与液体折射率的关系模型,实现了溶液质量分数的测量,并对其测量不确定度进行了分析.基于PDMS基片的液芯柱透镜对注入其中的液体折射率的最小分辨能力优于0.000 2 RIU,质量分数测量不确定度可控制在0.12%以内.该测量方法适用于微量液体折射率及质量分数的测量. 相似文献
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根据溶液中溶质的浓度变化将引起溶液折射率变化的特性,提出一种利用光学低相干干涉技术通过测量葡萄糖溶液的折射率来确定其浓度的方法。基于迈克尔逊干涉仪,建立了低相干光葡萄糖浓度检测系统,通过调节可移动角镜以产生干涉信号,根据角镜的位移量计算出光程,并进而求出折射率。实验结果表明:在LED光源光谱半高宽度为25nm,可移动角镜的移动步长为微米量级时,利用该方法对折射率的测量精度可以达到10-4数量级以上,对应的可以检测出低于100mg/d L的葡萄糖的浓度变化。过程方便快捷,受外界限制因素小,是一种有效的测量各种液体折射率及浓度的方法。 相似文献
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液体的折射率和液体的密度有直接关系,液体密度又与温度有关,根据已有关于透明介质的折射率公式,可得液体的膨胀系数的测量方法.迈克耳孙干涉法是测量液体折射率的温度系数的简捷的手段.用此方法得出了液体的膨胀系数,进而讨论了关于液体折射率的2个不同公式的精确程度. 相似文献
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为了得出光子晶体缺陷透射峰位置与溶液折射率及溶液浓度的关系,从而得知溶液的折射率和溶度之间的关系。本文构造了(AB)~NC(AB)~N型的一维光子晶体模型,采用时域有限差分法对该一维光子晶体的透射光谱做了数值模拟和分析。结果表明,蔗糖溶液折射率和浓度与光子晶体透过峰位置之间为严格的线性关系,光子晶体缺陷模透射峰位置随溶液浓度百分比的改变而变化。该溶液测量方法的溶液折射率测量灵敏度高达498.087 nm/RIU。这为光子晶体溶液折射率及浓度测量传感器的设计制作提供了参考,有助于该溶液浓度检测传感器在实际应用中的推广。 相似文献
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液体折射率是重要光学参数之一,液体折射率参数测量在食品生产鉴定、光学加工等领域都具有重要意义。本文基于便携式迈克尔逊干涉仪,在光学减震台上加装旋转微调载物台,综合考虑旋转后容器器壁、待测液体、空气中光程差的改变量,得到液体折射率的计算公式,与阿贝折射仪测量液体折射率的值进行比较,实验测得水、不同浓度的葡萄糖溶液以及不同浓度的氯化钠溶液,平均相对误差分别为1.1%、3.3%、2.0%,实验过程中测量的最大误差为5.9%,为液体折射率测量提供了一种可行方法,实现液体折射率的测量。本文也可作为迈克尔逊干涉仪的拓展实验,对本科生的创新能力培养有重要意义。 相似文献
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Luís Oliveira Armindo Lage M. Pais Clemente Valery Tuchin 《Optics and Lasers in Engineering》2009,47(6):667-672
Complete optical characterization of biological tissue is desirable to develop clinical methods using optical technologies. Particularly, to develop optical clearing methods in biological tissues, it is necessary to know the composition of the tissue, the percentage of each constituent and corresponding refractive indexes. To obtain such information for rat muscle, we used a simple method to characterize tissue constituents for both content percentage and refractive index. The study consisted on measuring mass with a precision weighting scale and the refractive index with an Abbe refractometer during tissue dehydration. With the collected data, we used a theoretical model to calculate the refractive index and percentage for both interstitial fluid and solid part of the rat muscle. The results obtained are in good agreement with data published by other authors, and were considered of vital information for the optical clearing studies that we planned to perform. 相似文献
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折射率调制型光纤传感器在溶液浓度测量中的应用 总被引:8,自引:0,他引:8
本文详细报道了用折射率调制型光纤传感器测量溶液浓度的原理及实验装置。为了消除光源光强的不稳定性对测量精度提高的影响,我们提出用光学双稳态装置稳定光源的输出功率并将它用于实际测量中,实验结果表明:本方法用于测量溶液的浓度在灵敏度、精度和稳定度方面都有较大的提高,并且可用于在线监测。 相似文献
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Due to many experimental data required and a lot of calculations involved, it is very complex and cumbersome to model prism-based liquid-refractive-index-measuring methods. We develop a new method of mathematical modelling for measuring refractive index of a liquid based upon the Fresnel formula and prism internal reflection at an incident angle less than the critical angle. With this method, only two different concentrations measurements for a kind of solution can lead to the determination of computational model. Measurements are performed to examine the validity of the theoretical model. Experimental results indicate the feasibility of the theoretical model with an error of 1%. The method is also capable of measuring even smaller changes in the optical refractive index of the material on a metal surface by the surface plasma resonance sensing techniques. 相似文献
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OCT图像法测量折射率 总被引:2,自引:0,他引:2
基于光程匹配原理提出了一种用光学相干断层成像(OCT)系统获得的图像测量样品折射率的方法。通过分析光程匹配原理,给出用OCT图像法测量样品折射率的原理及过程。以玻璃载波片和黄瓜组织为样品进行实验。实验结果表明,用OCT图像法获得的载玻片和黄瓜组织的折射率测量值分别为1.499和1.353,与发表或已知的折射率结果相吻合,测试结果的随机误差可小于0.01。另外,使用OCT图像法通过短时间所采集的两幅图像可对横向扫描任意位置的折射率同时进行测量。该方法进一步简化了基于光程匹配原理的折射率测量法的过程,缩短了测量时间,是一种快速测量样品折射率的实用方法。 相似文献
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A method that utilizes the Fresnel diffraction of light from the phase step formed by a transparent wedge is introduced for measuring the refractive indices of transparent solids, liquids, and solutions. It is shown that, as a transparent wedge of small apex angle is illuminated perpendicular to its surface by a monochromatic parallel beam of light, the Fresnel fringes, caused by abrupt change in refractive index at the wedge lateral boundary, are formed on a screen held perpendicular to the beam propagation direction. The visibility of the fringes varies periodically between zero and 1 in the direction normal to the wedge apex. For a known or measured apex angle, the wedge refractive index is obtained by measuring the period length by a CCD. To measure the refractive index of a transparent liquid or solution, the wedge is installed in a transparent rectangle cell containing the sample. Then, the cell is illuminated perpendicularly and the visibility period is measured. By using modest optics, one can measure the refractive index at a relative uncertainty level of 10(-5). There is no limitation on the refractive index range. The method can be applied easily with no mechanical manipulation. The measuring apparatus can be very compact with low mechanical and optical noises. 相似文献
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The Zygo interferometer for measuring refractive index of liquids such as heavy water is presented. The accuracy of measurement in the refractive index of liquids is found to be ±0.0002 in the Zygo interferometer. An application of Zygo interferometer for heavy water analysis is also presented. The interferometer is found to be useful for determining the percentage purity of heavy water with an accuracy of ±5% in the purity range of 0–100%. 相似文献
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High sensitivity refractive index gas sensing enhanced by surface plasmon resonance with nano-cavity antenna array
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The surface plasmon resonance gas sensor is presented for refractive index detection using nano-cavity antenna array.The gas sensor monitors the changes of the refractive index by measuring the spectral shift of the resonance dip,for modulating the wavelength of incident light.It is demonstrated that minute changes in the refractive index of a medium close to the surface of a metal film,owing to a shift in the resonance dip of the wavelength,can be detected.The average detection sensitivity is about 3200 nm/RIU(refractive index units),which is more than twice that of a metal grating-based gas sensor.The reflectivity of the surface plasmon resonance dip is only ~ 0.03%,and the full widths at half maximum(FWHMs) of bandwidth of the angle and wavelength are ~ 0.20° and 4.71nm,respectively. 相似文献
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用高亮度LED和线阵CCD在线自动测量溶液浓度 总被引:4,自引:0,他引:4
根据溶液浓度和折射率的对应关系及几何光学原理,利用CCD传感器的光电转换、信号存储、信号转移和信号读出等功能,可实现对溶液浓度的在线自动检测。为了提高测量精度,对测量系统的各组成部分进行了优化设计。通过对水和蔗糖溶液的多次测量,证明系统具有较好的重复性,稳定性和方便性,具有测量精度高,在线自动检测,非接触测量等特点。 相似文献