共查询到19条相似文献,搜索用时 156 毫秒
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设计并制作了一种基于单模-无芯-单模-无芯-单模光纤结构的马赫-曾德尔传感器,可用来同时测量折射率和温度.该传感器中,两处无芯光纤充当输入、输出耦合器,中间单模光纤作为传感臂.利用有限元仿真和理论分析,确定耦合器和传感臂的最优长度为15 mm.在无芯光纤中激发出的高阶模进入单模光纤的包层传输,由于倏逝场的作用,受到环境折射率和温度的影响.选取透射谱不同干涉级次的波谷作为研究对象,实现了折射率和温度的同步测量.实验结果表明:1545 nm附近干涉谷的折射率和温度灵敏度分别为–153.89 nm/RIU(refractive index unit)和0.166 nm/℃;1570 nm附近干涉谷的折射率和温度灵敏度分别为–202.74 nm/RIU和0.183 nm/℃.该传感器在实现折射率和温度同步测量的同时,仍能保持较高灵敏度,在生物医疗等方面有着较好的应用前景. 相似文献
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用毛细管焦点法精确测量微量液体的折射率 总被引:3,自引:0,他引:3
介绍了用毛细管焦点法精确测最微量液体折射率的一种新技术.该技术基于共轴球面光学系统的成像原理,用LED(λ=580 nm,FWHM为32nm)为测量光源,用CCD为像接收装置.一次测量样品需要量小于0.002 mL.待测样品封闭在毛细管内测量,有利于对毒性、挥发性和吸湿性强的液体介质折射率的测量.用此技术对纯水、乙醇、乙二醇和丙三醇样品的折射率做了测量,测量精度分别为0.0001,0.0002,0.0003和0.0003.论文在分析实验装置的测量灵敏度和成像景深基础上,提出了进一步提高测最精度的方法. 相似文献
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基于光纤M-Z干涉的高灵敏度液体折射率传感器的实验研究 总被引:1,自引:0,他引:1
提出并制备了一种基于Mach-Zehnder干涉效应的高灵敏度光纤液体折射率传感器.分别利用NaCl溶液和甘油溶液,研究了传感器的透射光谱和外界介质折射率的关系.实验结果表明,随着周围介质折射率的增大,传感器干涉谱的极小值点对应的波长向长波方向漂移,在1.333~1.356的折射率变化范围内,极小值点对应的波长的漂移量和折射率的变化具有较好的线性关系,对应的灵敏度约为4 086nm/refractive-index.该传感器制作简单、结构紧凑,在生物和化学测量中具有较好的应用前景. 相似文献
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提出并制备了一种基于Mach-Zehnder干涉效应的高灵敏度光纤液体折射率传感器.分别利用NaCl溶液和甘油溶液,研究了传感器的透射光谱和外界介质折射率的关系.实验结果表明,随着周围介质折射率的增大,传感器干涉谱的极小值点对应的波长向长波方向漂移,在1.333~1.356的折射率变化范围内,极小值点对应的波长的漂移量和折射率的变化具有较好的线性关系,对应的灵敏度约为4 086 nm/refractive-index.该传感器制作简单、结构紧凑,在生物和化学测量中具有较好的应用前景. 相似文献
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用液芯柱透镜测量液体折射率 总被引:2,自引:0,他引:2
制作了一种液芯变焦柱透镜并将其用于精确测量液体的折射率.在空心的柱透镜内注入待测折射率的液体,通过测量液芯透镜的焦距,根据焦距和折射率之间的关系,计算出液芯介质的折射率.此方法有效地提高了折射率测量的灵敏度,减小了测量系统的景深.选取×20倍显微物镜可实现液体折射率1.3~1.642范围内的精确测量,单次测量误差小于0.000 2. 相似文献
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基于多模光纤偏芯熔接实现温度和折射率同时测量的光纤传感器 总被引:1,自引:0,他引:1
利用偏芯熔接的方法,研制出一种可实现温度和折射率同时测量的光纤传感器。该传感器将一段多模光纤MMF2的左端与一芯径与长度均相同的多模光纤MMF1偏芯熔接,右端与一大芯径多模光纤MMF3对芯熔接构成传感头,利用多模光纤纤芯模和包层模对温度、折射率的敏感性差异,结合敏感矩阵实现了双参量同时测量。实验选取了位于1536.98nm和1545.24nm处的干涉谷进行了温度和折射率的测量,测得1536.98nm处的干涉谷对温度的灵敏度为0.105nm/℃,对折射率不敏感;1545.24nm处的干涉谷对温度的灵敏度为0.052nm/℃,对折射率的敏感性为32.2nm/RIU(RIU表示单位折射率)。该传感器也可应用于其他参量的测量,具有良好的应用前景。 相似文献
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提出了一种基于芯内双微孔复合结构的全光纤干涉传感器结构,建立了传感器反射光谱的理论模型,给出了反射光谱强度与微孔长度、孔内介质折射率、微孔端面反射与损耗系数以及光纤的特性参数间的关系,并模拟了传感器光谱对温度和折射率变化的响应特性.利用193 nm准分子激光器,在普通单模光纤上加工制作了具有复合腔结构的全光纤多参量传感器,进行了传感实验研究.结果表明,该传感器具有优于99%的温度、折射率线性响应度,对应两套温度和折射率灵敏度分别为-0.172 nm/℃,1050.700 nm/RIU和0.004 nm/℃,48.775 nm/RIU,不仅能够实现温度、折射率以及它们的区分测量,还能够应用于气体压力的测量,测量精度可达0.3 kPa. 相似文献
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We report on a novel method based on intracavity spontaneous mode locking to precisely measure the group refractive indices and temperature dependence of refractive index of Nd:YVO(4) crystal at the wavelength of 1064 nm. All the experimental results are found to agree very well with the most recent measured values. We also confirm that the developed method is applicable to measuring the group refractive indices and the temperature dependence of the refractive indices of other vanadate crystals, as well as nonlinear crystals. 相似文献
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Experimental techniques for measurement of optical penetration depth and refractive index of humantissue are presented, respectively. Optical penetration depth can be obtained from the measurement ofthe relative fluence-depth distribution inside the target tissue. The depth of normal and carcinomatoushuman lung tissues irradiated with the wavelengths of 406.7, 632.8 and 674.4 nm in vitro are respectivelydetermined.In addition,a novel simple method based on total internal reflection for measuring therefractive index of biotissue in vivo is developed,and the refractive indices of skin from people of differentage, sex and skin color are measured.Their refractive indices are almost same and the average is 1.533. 相似文献
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S. P. Pogossian H. Le Gall E. A. Arutunian S. Kh. Galoyan M. Maaza 《Optical and Quantum Electronics》1993,25(10):695-698
A new experimental method is proposed for measuring the refractive indices of liquids based on mode line measurements. The experimental setup consists of a dielectric substrate in which a rectangular hollow is formed containing the concerned liquid. This is covered by a trapezium-shaped prism. The liquid, confined between both basin walls and the prism, forms a wavegude. Thus, the refractive index of the liquid can be determined by measuring the propagating modes in the structure. Using this technique, the refractive indices of liquids can be measured to an accuracy of the order of 1×10-4. 相似文献
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Diffuse reflection spectra of biotissues in vivo and transmission and reflection coefficients for biotissues in vitro are
measured over 300–800 nm. These data are used to determine the spectral absorption and scattering indices and the scattering
anisotropy factor for stomach mucous membranes under normal and various pathological conditions (chronic atrophic and ulcerous
defects, malignant neoplasms). The most importan tphysiological (hemodynamic and oxygenation levels) and structural-morphological
(scatterer size and density) parameters are also determined. The results of a morphofunctional study correlate well with the
optical properties and are consistent with data from a histomorphological analysis of the corresponding tissues. 相似文献
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A method for computer modeling of transmission and diffuse reflection of a strongly scattering biotissue is described. Results of calculations of spectral characteristics for a model of the human eye sclera are presented and compared with experiments. The possibility to control optical properties of biotissues is theoretically substantiated and experimentally confirmed. Variations in color indices of biotissues are calculated using theoretical and experimental spectral characteristics obtained for the eye sclera. 相似文献
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J. R. Shi Y. C. Xu P. Z. Zhou M. Z. Zhao 《Zeitschrift für Physik B Condensed Matter》1990,79(2):177-179
An experimental method is proposed for measuring the refractive indices of anisotropic crystals. The results of the first measurements are in good agreement with those of other methods. 相似文献
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基于二次彩虹法用三种不同波长(632.8 nm、532 nm、404 nm)的激光测量了玻璃微珠的折射率,并由柯西色散公式拟合得到三种典型高折射率玻璃微珠1.90、1.93和2.2的色散方程,得出现行的玻璃微珠具有正常色散但色散较大的结论.通过分析在不同入射角情况下,色散对玻璃微珠回归反射性能的影响,得出折射率1.90和1.93的玻璃微珠具有优良的回归反射性能.此外,用光线追迹模拟了色散对回归反射后光能量在近轴区域分布的影响,折射率1.90和1.93的玻璃微珠回归反射光线的能量主要集中在5°范围内. 相似文献
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Multiple-beam interference fringes of equal chromatic order are produced in air and liquid sample interferometric gaps. The two gaps are of the same thickness and simultaneously enclosed in a wedge interferometer. A single shot interferogram containing fringes in the two gaps is sufficient to deduce the needed experimental data. Locations of the fringe maxima, in the two gaps, are introduced in a non-numerical procedure for determining the gap thickness and the liquid-phase refractive indices across the visible spectrum. The method has been used for measuring the phase refractive indices of human blood-serum, saliva, sweat, urine and water liquids. A third-order polynomial dispersion relation is applied for fitting the measured phase indices. Group refractive indices have been derived and fitted to the same dispersion formula. 相似文献