共查询到17条相似文献,搜索用时 203 毫秒
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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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基于米氏散射理论解释了激光照明下玻璃微珠的二次彩虹精细结构的成因,发现折射率的差异将直接影响二次彩虹精细结构的位置.对于实验中玻璃微珠半径变化引起二次彩虹精细结构间距变化的现象亦用米氏散射理论进行了模拟分析和实验研究.利用米氏散射的近似理论——艾里理论对玻璃微珠的折射率进行了测量.在对玻璃微珠二次彩虹精细结构所计算得到的折射率的统计分析基础上,通过校正测量误差后得到了玻璃微珠折射率的准确数据. 相似文献
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基于几何光学原理,彩虹法使用激光作为光源,利用激光在玻璃微珠中进行一次或者多次内反射后出射形成最小偏向角,在最小偏向角附近形成彩虹条纹,通过测量彩虹条纹来反演计算玻璃微珠的折射率。然而,成像法则根据厚透镜的成像原理,对玻璃微珠所成的像经过显微物镜放大后使用CCD相机进行接收,获得玻璃微珠的焦距,进而测得对应玻璃微珠的折射率。较传统方法来说,彩虹法和成像法具有安全、简便和快捷的优点。对型号不同的玻璃微珠,分别使用彩虹法和成像法测量其折射率,并对它们的测量结果进行了对比分析,都获得相对于名义值的误差小于1%的结果。 相似文献
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《中国光学与应用光学文摘》2006,(5)
O435.12006053853二次彩虹法高折射率玻璃微珠的折射率测量研究=Studyon refractive index measurement of high refractive indexglass beads by secondary rainbow method[刊,中]/杨宏坤(四川大学电子信息学院.四川,成都(610064)),李大海…//激光杂志.—2006,27(2).—52-53通过对高折射率玻璃微珠在激光照明下形成的二次彩虹的实验研究,提出了一种激光照明下高折射率玻璃微珠二次彩虹条纹图的获取装置。以艾里的虹理论为基础,提出了一种由二次彩虹条纹图确定最小偏向角的方法,实现了高折射玻璃微球折射率的测量。实验证明,该方法的测量精… 相似文献
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《Chinese Journal of Physics (Taipei)》2018,56(5):2350-2356
We theoretically study and propose the design concept of a new non-contact measurement method of the thickness and refractive index of dielectric film. The needed measurement set-up includes a probe, an optical detection head and a spectrometer. The probe is composed of two patches of dielectric substrates, and the optical detection head is used to detect the reflective spectra. After depositing a testing dielectric film on the two patches, the coating film thickness and refractive index can be determined by analyzing the normal-incidence reflective spectra of the two dielectric substrates. This method has two requirements. First, the coating dielectric films on the two substrates must be the same. Second, the two dielectric substrates respectively have higher and lower refractive indices than the testing dielectric film. 相似文献
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反射式光纤表面等离子体波共振传感器特性研究 总被引:1,自引:1,他引:1
研究了一种基于表面等离子体波共振(SPR)光谱分析的折射率检测新方法。研究发现,表面等离子体波共振效应光谱特征的折射率灵敏度会随着液体性质变化而发生改变。根据折射率测量范围不同,分别选择共振波长和共振强度作为检测参量,实现理论折射率分辨力达到10~(-5)数量级以上。在理论分析和实验基础上,设计出一种基于共振光强检测的终端反射式光纤表面等离子体波共振效应传感系统,采用将传感信号和基准光信号的比值作为液体折射率变化的度量值。在1.3325~1.3991的折射率测量范围内,度量值与折射率之间呈现单调递减关系,线性相关系数为0.9983。通过定义耦合系数,还可实现对表面等离子体波共振效应效应强弱和变化趋势的评估。 相似文献
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A high-resolution sensor for measuring the refractive index of liquids using a reflective arrayed-waveguide grating (AWG) is proposed. The refractive index of a liquid placed in the groove of the arrayed region is measured via the shift of the maximum intensity in the imaging plane of the AWG owing to the phase change in the region. The refractive index can be monitored in real time by measuring the power ratio between two output waveguides of the AWG with a narrow-band source. A mathematical model based on Fourier optics and wave optics is established. A fitting formula for the relationship between the power ratio and the refractive index of liquid is derived. The results of the study show that the proposed method can eliminate the effects of instability of the light source and the inner loss of the system and provide a refractive index resolution of 10−7. 相似文献
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周期性结构是光学薄膜设计的基本物理模型,给出了反射区中心波长的一般性条件,研究了在膜层材料存在折射率色散情况下,等厚周期结构和非等厚周期结构的薄膜反射区中心波长与带宽特性.研究结果表明:在等厚和非等厚周期结构中,考虑膜层材料折射率色散与忽略色散情况相比,中心波长向长波方向移动,反射级次与相对波数的线性关系偏离;在薄膜光学厚度一定的非等厚周期结构中,高折射率层光学厚度大于低折射率层时,反射级次与相对波数的线性关系偏离度高;非等厚周期结构薄膜的带宽在低反射级次上小于等厚周期结构,同时膜层的色散对反射带宽影响不大. 相似文献
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Design of an optoelectronic refractometer having an adjustable range of refractive index measurement
R.K. Shukla Atul Srivastava Anchal Srivastava Manoj Srivastava Shobhna Dixit D. Misra 《Optics & Laser Technology》2008,40(5):692-696
A real-time optoelectronic refractometer having an adjustable range of refractive index measurement is presented. The adjustment is achieved by obtaining a shift in the zero-reflected intensity point at the interface following the introduction of a glass plate of refractive index different from that of the constituent prism. The sensitivity remains reasonably high over the enhanced range of refractive index measurement. The experimental results are in qualitative agreement with the theoretical calculations. This refractometer sensor, which is based on the detection of modulation in emergent light intensity, has a sturdy and user-friendly design. 相似文献
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The refractive index profile of an axially symmetric fiber preform is determined by using the transport of intensity equation. In this method the preform is immersed in an index-matching liquid, and a collimated light beam impinges on it laterally. The intensity distributions of the transmitted light are measured on two close parallel planes inside the preform core. From the recorded intensity distributions, the deflection function is calculated by the transport of intensity equation. The refractive index profile is obtained by means of Abel inversion. Also, for comparison, the refractive index profile of the preform is measured by the focusing method and the results are in agreement with less than 3% error. 相似文献