Journal articles: 'Refractive index'

1

Koike, Yasuhiro. "Refractive index, refractive index distribution, birefringence." Kobunshi 37, no. 10 (1988): 768–71. http://dx.doi.org/10.1295/kobunshi.37.768.

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Supriyadi, Supriyadi, Misto Misto, and Yulia Hartanti. "Palm Cooking Oil Refraction Index Measurement Using Single Slit Fraunhofer Diffraction Method." Jurnal ILMU DASAR 15, no. 2 (August 7, 2015): 97. http://dx.doi.org/10.19184/jid.v15i2.632.

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Palm cooking oil refraction index measurement has been done in several temperature using single slit Fraunhofer diffraction method. Ratio between diffraction patterns at the air dan solution medium can be used to determine its refraction index. Using aquades as sample, was obtained refractive index 1.331 with the discrepancy 0.038%. Based on the refractive indexs measured for each temperature were obtained linear equation model: Y=-(0,00145±0,00021)X+(1,54232±0,01757)where R = -0,97266 and R^2=0,94606. Temperature changes influence strongly to refractive index changes of palm cooking oil sample, changes both inversely. Gradient of 0.00145 indicate that refractive index of palm cooking oil sample decrease slowly, so the quality is still good. Keywords : Palm Coocing oil, refractive index, temperature, Fraunhofer diffraction method

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Qin, Yonggang, Xiaobo Feng, and Yu Liu. "Nonlinear Refractive Index in Rectangular Graphene Quantum Dots." Applied Sciences 9, no. 2 (January 17, 2019): 325. http://dx.doi.org/10.3390/app9020325.

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Alongside its other favorable properties, the large refraction nonlinearity of graphene-related material makes it ideal for use in optoelectronics applications. Numerous experimental studies about nonlinear optical refraction have been conducted, but theoretical verification is lacking. In this paper the nonlinear refractive index for rectangular graphene quantum dots (RGQDs) was calculated using the relationship between nonlinear refractive index and the third-order nonlinear optical susceptibility. The third-order nonlinear optical susceptibility for third harmonic generation was derived employing the electronic states obtained from the Dirac equation around K point in RGQDs under hard wall boundary conditions. Results revealed that the calculated nonlinear refractive index, n 2 , was in the magnitude of 10−14 m2/W in the visible region, which is nearly five orders larger than conventional semiconductor quantum dots, while in the infrared region the nonlinear refractive index reached up to the magnitude of 10−11 m2/W for M = 3M0 sized RGQDs where the resonance enhancement occurred. The nonlinear refractive index could be tuned both by the edges and sizes.

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Trofimov V., Rosanov N. N., Yang Y., Fedorov S. V., Yu J., and Veretenov N. A. "Refraction by gas inhomogeneities during laser heating of a metal." Optics and Spectroscopy 130, no. 4 (2022): 469. http://dx.doi.org/10.21883/eos.2022.04.53739.55-21.

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An analysis is made of the distribution of the refractive index near the boundary of a metal heated by laser radiation. The gradient of the refractive index of the gas, caused by the heat flux, and the distribution of the refractive index in the inhomogeneously heated gas are found. The drift of the laser beam due to the refraction of radiation in a gas is estimated, which shows an increase in the drift for narrow laser beams. Keywords: refraction in gas, gas heating, metal laser heating.

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Gutiérrez, Cristian E., and Eric Stachura. "Uniform refraction in negative refractive index materials." Journal of the Optical Society of America A 32, no. 11 (October 20, 2015): 2110. http://dx.doi.org/10.1364/josaa.32.002110.

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Maru, Koichi. "Design of Transmission-Type Refractive Index Sensor, Based on Silica Planar Lightwave Circuit Using Combination of Refractive Angle and Phase Measurements." Sensors 19, no. 19 (September 22, 2019): 4095. http://dx.doi.org/10.3390/s19194095.

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A transmission-type refractive index sensor, based on planar lightwave circuit (PLC) technology is proposed. In the proposed structure, we introduce a combination of coarse measurements, using the dependence of the angle of refraction and fine measurement, and the dependence of the phase on the refractive index to measure the absolute refractive index precisely, without expensive optical measurement equipment. The theoretical model of the proposed refractive index sensor is derived based on Fourier optics and transfer function to simulate its performance. The simulation results for the use of the 2.5%-Δ silica-based PLC technology indicate that the proposed structure has the potential to achieve a refractive index error of approximately 1 × 10−6 RIU or less when a monitored power deviation of ±0.05 dB is accepted.

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ZHANG, YONG, and A. MASCARENHAS. "TOTAL AND NEGATIVE REFRACTION OF ELECTROMAGNETIC WAVES." Modern Physics Letters B 19, no. 01n02 (January 20, 2005): 21–33. http://dx.doi.org/10.1142/s0217984905008074.

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Recently there has been a great deal of interest in an unusual category of material, that is, a material that exhibits negative refractive index or more generally negative group velocity. Perhaps the most immediate application of this type of material is in an area known as total and negative refraction, which may potentially lead to many novel optical devices. The reason that the phenomenon of total and negative refraction has become so interesting to the physics community is also due largely to the notion that this phenomenon would never occur in conventional materials with positive refractive index. It turns out that total and negative refraction can be realized even in natural crystalline materials or in artificial materials (e.g. photonic crystals) without negative (effective) refractive index. In this brief review, after providing a brief historic account for the research related to finding materials with negative group velocity and achieving negative refraction, we discuss the three primary approaches that have yielded experimental demonstrations of negative refraction, in an effort to clarify the underlying physics involved with each approach. A brief discussion on the subwavelength resolution application of the negative (effective) refractive index material is also given.

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Zheng, Yuan, Kexun Shen, Xianghe Wang, and Xing-Xing Yao. "Rainbows in Different Refractive Indices." Physics Teacher 61, no. 5 (May 1, 2023): 351. http://dx.doi.org/10.1119/5.0086915.

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The rainbow is a natural optical scattering and dispersion phenomenon that reveals the visible spectral composition of sunlight in the shape of an arc. People are instinctively attracted by its colorful appearance and curved shape. Hence, there are many serious studies about the rainbow with a long history. Recently, several simple experiments, adopting glass balls, acrylic spheres, spherical flasks, or sessile water drops, have been devised to demonstrate how the rainbow is formed. These works demonstrate the colors and shapes of the rainbow well and explain how the dispersive spectrum is produced by the refraction–reflection–refraction process. However, the influence of the refractive index is rarely illustrated. It is not difficult to see that the refractive index of raindrops and the atmosphere is closely related to the rainbow, especially the viewing angle of it. In this paper, we use spherical lenses with different materials and in different solutions to change the refractive index. Under a collimated light source, the evolution of the viewing angles of primary and secondary rainbows with respect to the refractive index is demonstrated. Experiments with refraction conditions similar to a natural rainbow are also conducted.

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9

Rogers, John R., and Mark D. Hopler. "Conversion of group refractive index to phase refractive index." Journal of the Optical Society of America A 5, no. 10 (October 1, 1988): 1595. http://dx.doi.org/10.1364/josaa.5.001595.

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Zhao, Xin Yi, Yu Feng Peng, Cong Cong Zhai, Xue Yun Han, and Yi Zhang. "Influence of Inorganic Salts on the Refraction Index of Water." Applied Mechanics and Materials 716-717 (December 2014): 118–21. http://dx.doi.org/10.4028/www.scientific.net/amm.716-717.118.

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The refractive index of double-distilled water and inorganic salt solutions of concentrations varying from 0.4 to 100 ppt (‰) have been measured at 20 Celsius degrees using Abbe refractometer, respectively. The inorganic salts such as NaCl, MgSO4, KCl and MgCl2,these forming the major constituents of seawater are used as solutes of the water solution. The effect of the concentration of these constituents on the refractive index of the solution is experimentally investigated. And meanwhile, the index of refraction studies are carried out for the laser wavelength of 405nm, 450nm, 532nm and 633nm under the case of varying concentration. The results show that the refractive index of the solution will be linearly increased with the increase of the concentration of these constituents. The index of refraction differs for the different solutes when their concentration is same at a certain wavelength.

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Mai, Yanbo, Zheng Sheng, Hanqing Shi, and Qixiang Liao. "Using Improved XGBoost Algorithm to Obtain Modified Atmospheric Refractive Index." International Journal of Antennas and Propagation 2021 (September 23, 2021): 1–11. http://dx.doi.org/10.1155/2021/5506599.

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Atmospheric refraction is a special meteorological phenomenon mainly caused by gas molecules and aerosol particles in the atmosphere, which can change the propagation direction of electromagnetic waves in the atmospheric environment. Atmospheric refractive index, an index to measure atmospheric refraction, is an important parameter for electromagnetic wave. Given that it is difficult to obtain the atmospheric refractive index of 100 meters (m)–3000°m over the ocean, this paper proposes an improved extreme gradient boosting (XGBoost) algorithm based on comprehensive learning particle swarm optimization (CLPSO) operator to obtain them. Finally, the mean absolute percentage error (MAPE) and root mean-squared error (RMSE) are used as evaluation criteria to compare the prediction results of improved XGBoost algorithm with backpropagation (BP) neural network and traditional XGBoost algorithm. The results show that the MAPE and RMSE of the improved XGBoost algorithm are 39% less than those of BP neural network and 32% less than those of the traditional XGBoost. Besides, the improved XGBoost algorithm has the strongest learning and generalization capability to calculate missing values of atmospheric refractive index among the three algorithms. The results of this paper provide a new method to obtain atmospheric refractive index, which will be of great reference significance to further study the atmospheric refraction.

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Paroha, P. P. "Variation in refractive index of sugar solution with concentration using Newton’s rings." YMER Digital 21, no. 06 (June 29, 2022): 1129–32. http://dx.doi.org/10.37896/ymer21.06/a8.

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Refractive index or index of refraction is an important physiochemical property of an optical medium. Here we report its value for sugar solution of various concentrations (0%, 5%, 10% and 20%) using the Newton’s rings set up for yellow light from sodium lamp (λ=5893Å). Newton’s Rings are an interference pattern generated via division of amplitude principle. The set-up used in our study is easily available in an undergraduate laboratory. The study correctly presents effect of increasing number of particles in a liquid on its refractive index. KEY WORD: Newton’s Rings, refractive index, interference and sugar solution.

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Arron, Brett L., Mark R. Ph Paulson, and Eric Jacobsohn. "OPTICAL REFRACTIVE INDEX." Anesthesiology 89, Supplement (September 1998): 1230A. http://dx.doi.org/10.1097/00000542-199809200-00059.

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14

Bhattacharya, J. C. "Refractive index measurement." Optics & Laser Technology 19, no. 1 (February 1987): 29–32. http://dx.doi.org/10.1016/0030-3992(87)90008-9.

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Aziz, Shujahadeen B., Sarkawt Hussein, Ahang M. Hussein, and Salah R. Saeed. "Optical Characteristics of Polystyrene Based Solid Polymer Composites: Effect of Metallic Copper Powder." International Journal of Metals 2013 (December 12, 2013): 1–6. http://dx.doi.org/10.1155/2013/123657.

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Solid polymer composites (SPCs) were prepared by solution cast technique. The optical properties of polystyrene doped with copper powder were performed by means of UV-Vis technique. The optical constants were calculated by using UV-Vis spectroscopy. The dispersion regions were observed in both absorption and refractive index spectra at lower wavelength. However, a plateau can be observed at high wavelengths. The small extinction coefficient compared to the refractive index reveals the transparency of the composite samples. The refractive index and optical band gap were determined from the reflectance and optical absorption coefficient data, respectively. The nature of electronic transition from valence band to conduction band was determined and the energy band gaps of the solid composite samples were estimated. It was observed that, upon the addition of Cu concentration, the refractive index increased while the energy gaps are decreased. The calculated refractive indexes (low index of refraction) of the samples reveal their availability in waveguide technology.

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Ma, Zhao Yang, and Ben Ning Qu. "Application of Digital Image Correlation in Measuring Refraction Index of Transparent Material." Applied Mechanics and Materials 723 (January 2015): 727–31. http://dx.doi.org/10.4028/www.scientific.net/amm.723.727.

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This article describes a method to measure the refraction index of transparent material by combining the characteristics of transparent material with 2D digital image correlation. The method established the relationship between refraction index and in-plane displacement of speckles using the refraction principle. In-plane displacement can be calculated by the 2D digital image correlation directly. Refractive index of PMMA were obtained by speckle patterns which were recorded by single camera. Results showed that the calculation is very close to the existing PMMA material refractive index value that proved the feasibility and the effectiveness of the method. Of course, this method also can be used to calculate the thickness of the transparent material to widen its using fields.

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Suri, Gunjan, Gouri Shankar Jha, Geetha Seshadri, and Rakesh Kumar Khandal. "Modification of Low Refractive Index Polycarbonate for High Refractive Index Applications." International Journal of Polymer Science 2009 (2009): 1–8. http://dx.doi.org/10.1155/2009/836819.

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Polycarbonates and polythiourethanes are the most popular materials in use today, for optical applications. Polycarbonates are of two types which fall in the category of low refractive index and medium refractive index. The present paper describes the conversion of low refractive index polycarbonates into high refractive index material by the use of a high refractive index monomer, polythiol, as an additive. Novel polycarbonates, where the properties of refractive index and Abbe number can be tailor made, have been obtained. Thermal studies and refractive index determination indicate the formation of a new polymer with improved properties and suitable for optical applications.

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Ilhami, Fasih Bintang, and Mohammad Budiyanto. "The Characterization of Salt Level in Mango Fruit Through Principle of Refraction Index." Science Education and Application Journal 5, no. 1 (March 25, 2023): 56. http://dx.doi.org/10.30736/seaj.v5i1.752.

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The characterization of salt levels in fruits with simple techniques still has several challenges to determine. Herein, we successfully present a simple breakthrough to resolve of purity or concentration of a substance by the principle of refraction index with a refractometer. The resulting experiments by mango fruit extracts showed refractive index is produced in NaCl solution at a concentration of 0.1 M; 0.2M; 0.5M; 1 M; 2 M by 1004; 1009; 1016.3; 1017.3; 1058, respectively. More importantly, the highest refractive index produced in mango fruit extract is owned by Manalagi mango with a refractive index of 1047.3, followed by Arum Manis mango with 1041, Banjarnegara mango with 1030, Gadung mango with 1023.3, and Raw mango with 1015,3. Thus, the higher the concentration of the solution would the greater the refractive index produced due to refractive index is inversely proportional to the speed of light in the solution. Therefore, this is a simple technique that can be used to determine salt levels in fruits and allow to select healthy fruit for intake by our body.

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Jen, Yi-Jun, and Wei-Chin Liu. "Design a Stratiform Metamaterial with Precise Optical Property." Symmetry 11, no. 12 (December 1, 2019): 1464. http://dx.doi.org/10.3390/sym11121464.

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In this work, a stratiform metamaterial is arranged as multiple periods of metal-dielectric symmetrical film stack to provide precise equivalent refractive index and admittance. There are multiple solutions of equivalent refractive index retrieved from the characteristic matrix of the film stack. The correct refractive index is derived by connecting different branches of solution at different ranges of wavelength or thickness of the dielectric layer. The refractive index of an Ag-TiO2 five-layered symmetrical film stack shown in previous work is demonstrated to be positive real instead of negative real. The associated type I iso-frequency curve supports negative refraction. In order to extend the operating wavelength of type I metamaterial, the number of the metal-dielectric symmetrical film stack is increased to reduce the thickness of the dielectric film to approach subwavelength requirement.

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Nguyen, Dung Tien, Le Canh Trung, Nguyen Duy Cuong, Ho Dinh Quang, Dinh Xuan Khoa, Nguyen Van Phu, Chu Van Lanh, Nguyen Thanh Vinh, Do Thanh Thuy, and Bui Dinh Thuan. "Measuring the refractive index of a methanol - water mixture according to the wavelength." Photonics Letters of Poland 13, no. 1 (March 31, 2021): 10. http://dx.doi.org/10.4302/plp.v13i1.1058.

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The refractive index of the methanol-water mixture depending on the wavelength at different concentrations was determined by our experimental method using a Michelson interferometer system. A comparative study of Gladstone-Dale, Arago–Biot and Newton relations for predicting the refractive index of a liquid has been carried out to test their validity for the methanol-water mixture with the different concentrations 30%, 40%, 50%, 60%, 80%, and 100%. The comparison shows the good agreement between our experimental results and the results in the expressions studied over the wavelength range approximately from 450 to 850 nm. Full Text: PDF ReferencesS. Sharma, P.B. Patel, R.S. Patel, "Density and Comparative Refractive Index Study on Mixing Properties of Binary Liquid Mixtures of Eucalyptol with Hydrocarbons at 303.15, 308.15 and 313.15 K", E-Journal of Chemistry 4(3), 343 (2007). CrossRef A. Gayathri, T. Venugopal, R. Padmanaban, K. Venkatramanan, R. Vijayalakshmi, "A comparative study of experimental and theoretical refractive index of binary liquid mixtures using mathematical methods", IOP Conf. Series: Materials Science and Engineering 390, 012116 (2018). CrossRef A. Jahan, M.A. Alam, M.A.R. Khan, S. Akhtar, "Refractive Indices for the Binary Mixtures of N, N-Dimethylformamide with 2-Butanol and 2-Pentanol at Temperatures 303.15 K, 313.15 K, and 323.15 K", American Journal of Physical Chemistry 7(4), 55 (2018). CrossRef N. An, B. Zhuang, M. Li, Y. Lu, Z. Wang, "Combined Theoretical and Experimental Study of Refractive Indices of Water–Acetonitrile–Salt Systems", J. Phys. Chem. B 119(33), 10701 (2015). CrossRef M. Upadhyay, S.U. Lego, "Refractive Index of Acetone-Water mixture at different concentrations", American International Journal of Research in Science, Technology, Engineering & Mathematics 20(1), 77 (2017). CrossRef T.H. Barnes, K.Matsumoto, T. Eiju, K. Matsuda, N. Ooyama, "Grating interferometer with extremely high stability, suitable for measuring small refractive index changes", Appl. Opt. 30, 745 (1991). CrossRef B. W. Grange, W. H. Stevenson, R. Viskanta, "Refractive index of liquid solutions at low temperatures: an accurate measurement", Applied Optics 15(4), 858 (1976). CrossRef P. Hlubina, "White-light spectral interferometry with the uncompensated Michelson interferometer and the group refractive index dispersion in fused silica", Optics Communications 193(1-6), 1 (2001). CrossRef P. Hlubina, W. Urbanczyk, "Dispersion of the group birefringence of a calcite crystal measured by white-light spectral interferometry", Meas. Sci. Technol. 16(6), 1267 (2005). CrossRef P. Hlubina, D. Ciprian, L. Knyblová, "Direct measurement of dispersion of the group refractive indices of quartz crystal by white-light spectral interferometry", Optics Communications 269(1), 8 (2007). CrossRef S. R. Kachiraju, D. A. Gregory, "Determining the refractive index of liquids using a modified Michelson interferometer", Optics & Laser Technology 44(8), 2361 (2012). CrossRef F. Gladstone, D. Dale, "XXXVI. On the influence of temperature on the refraction of light", Philos. Trans. R. Soc. 148, 887 (1858). CrossRef D.F.J. Arago, J.B. Biot, Mem. Acad. Fr. 15, 7 (1806). CrossRef Kurtz S S and Ward A L J, "The refractivity intercept and the specific refraction equation of Newton. I. development of the refractivity intercept and comparison with specific refraction equations", Franklin Inst. 222, 563-592 (1936). CrossRef K. Moutzouris, M. Papamichael, S. C. Betsis, I. Stavrakas, G. Hloupis, D. Triantis, "Refractive, dispersive and thermo-optic properties of twelve organic solvents in the visible and near-infrared", Appl. Phys. B 116, 617 (2013). CrossRef S. Kedenburg, M. Vieweg, T. Gissibl, H. Giessen, "Linear refractive index and absorption measurements of nonlinear optical liquids in the visible and near-infrared spectral region", Opt. Mater. Express 2(11), 1588 (2012). CrossRef

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Bektanov, Bolatbek, Omar Sarybayev, Gauhar Serikbayeva, and Azamat Kaldybekov. "STUDY OF ATMOSPHERE INFLUENCE ON RESULTS OF DISTANCE MEASUREMENTS." Interexpo GEO-Siberia 9 (2019): 137–43. http://dx.doi.org/10.33764/2618-981x-2019-9-137-143.

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The article describes a method based on the relationship of the integral index of refraction of air with its integral altitude gradient. The refractive index N and its altitude gradient dN / dH are proportional to each other under conditions of limited atmospheric height. It has been established that the gradient of the refractive index can be found by the index itself with a known coefficient of coupling between them. Wherein, it is easy to find the gradient by the angle of complete refraction. Results of experimental studies and recommendations for its use are given. A correlation analysis of the results of synchronous measurements was performed.

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Liu, Wei, Hechao Liu, Lixia Chen, and Fan Zhang. "Study on the Performance of Sunflower Quasi-Periodic Photonic Crystal Superlens." Crystals 12, no. 8 (August 12, 2022): 1134. http://dx.doi.org/10.3390/cryst12081134.

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A study for the performance of the Sunflower (circular symmetric structure) quasi-periodic photonic crystal superlens is presented. A series of parameters, including thickness, refractive index and duty cycle, of the Sunflower structure are discussed. The analysis of this study illustrates that the Sunflower structure could provide excellent focusing imaging due to its good circular symmetry and also have negative refraction in low refractive index materials. It provides an important way to choose an alternative to positive refraction lenses in the future.

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Guo, Tao, and Zeng Ping Liu. "Light Capacitance Type Refractometer to Measure Atmosphere Parameter." Applied Mechanics and Materials 367 (August 2013): 297–301. http://dx.doi.org/10.4028/www.scientific.net/amm.367.297.

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The precise measure of atmospheric refractive index is one of the key factors which leads a guarantee of accurate estimate in the atmospheric refraction error margin and the forecast of atmosphere wave in the electronics systems, such as radar and correspondence...etc.. The error of 59 radiosonde which are in common used to measure atmospheric refractive refraction index is bigger, the microwave refract meter which has high accuracy also has the characteristics of high expenses, big weight of the instrument, those all bring very big restriction to engineering physically applications. For this cause, according to the principle that the variety of atmospheric refractive index brings frequency to the LC shock loop which composed by fixed inductance and air capacitor, this paper designs a light capacitance type refract meter which is use low temperature degree coefficient air capacitor for measure of sensitive component. Experiment validated: The precision of light capacitance type refract meter is more better than 59 radiosonde in measuring atmospheric refractive index, and it has no space-time measure error when sending out the temperature, wet, pressure respectively which is common find in 59 radiosonde, and it has advantages like light weight, small lag coefficient etc.

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Jiang, Jijuan, Yang Jia, Tong Wu, and Yachen Gao. "Transformation from Self-Focusing to Self-Defocusing of Silver Nanoparticles." Nanomaterials 11, no. 10 (September 24, 2021): 2485. http://dx.doi.org/10.3390/nano11102485.

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The nonlinear refraction of silver nanoparticles (AgNPs) in n-hexane was studied by using the closed-aperture Z-scan technique with a 532 nm nanosecond laser. It was found that, the nonlinear refraction of AgNPs shows the coexistence and transformation from self-focusing to self-defocusing. Specifically, self-focusing occurs at low excitation intensity, self-defocusing occurs at high excitation intensity, and coexistence of self-focusing and self-defocusing occurs at relatively moderate excitation intensity. The experimental results were analysed and discussed in terms of third-order and fifth-order nonlinear refractive effect. Specifically, the self-focusing is caused by the positive third-order nonlinear refraction, the self-defocusing is induced by the negative fifth-order nonlinear refraction, and the transformation from the self-focusing to self-defocusing at medium excitation intensity is caused by the competition of third-order and fifth-order nonlinear refraction. Finally, the third-order refractive index and fifth-order refractive index were obtained.

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Liu, Chunlan, Xin Zhang, Yachen Gao, Yong Wei, Ping Wu, Yudong Su, and Peng Wu. "Fiber SPR refractive index sensor with the variable core refractive index." Applied Optics 59, no. 5 (February 7, 2020): 1323. http://dx.doi.org/10.1364/ao.380665.

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Haque, Emranul, Md Anwar Hossain, Yoshinori Namihira, and Feroz Ahmed. "Microchannel-based plasmonic refractive index sensor for low refractive index detection." Applied Optics 58, no. 6 (February 20, 2019): 1547. http://dx.doi.org/10.1364/ao.58.001547.

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Lv, Hao, Aimei Liu, Jufang Tong, Xunong Yi, and Qianguang Li. "Gradient refractive index square lenses I Fabrication and refractive index distribution." Journal of the Optical Society of America A 26, no. 5 (April 1, 2009): 1085. http://dx.doi.org/10.1364/josaa.26.001085.

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Al-Ani, S. K. J., and C. A. Hogarth. "Correlation of refractive index and density in high refractive index glasses." Journal of Materials Science Letters 6, no. 5 (May 1987): 519–21. http://dx.doi.org/10.1007/bf01739271.

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Zhao, Sihai. "Method for refractive index detection for emulsion concentration." Functional materials 25, no. 2 (June 27, 2018): 401–5. http://dx.doi.org/10.15407/fm25.02.401.

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Seow, Y. C., S. P. Lim, B. C. Khoo, and H. P. Lee. "An optofluidic refractive index sensor based on partial refraction." Sensors and Actuators B: Chemical 147, no. 2 (June 3, 2010): 607–11. http://dx.doi.org/10.1016/j.snb.2010.03.076.

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Bednarek, Stanislaw. "Prism with a variable refraction angle and refractive index." Physics Education 28, no. 4 (July 1993): 256–57. http://dx.doi.org/10.1088/0031-9120/28/4/013.

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Zhang, Qingpeng, Yi Tan, Ge Ren, and Tao Tang. "Ray Tracing Method of Gradient Refractive Index Medium Based on Refractive Index Step." Applied Sciences 11, no. 3 (January 20, 2021): 912. http://dx.doi.org/10.3390/app11030912.

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For gradient refractive index media with large refractive index gradients, traditional ray tracing methods based on refined elements or spatial geometric steps have problems such as low tracing accuracy and efficiency. The ray tracing method based on refractive index steps proposed in this paper can effectively solve this problem. This method uses the refractive index step to replace the spatial geometric step. The starting point and the end point of each ray tracing step are on the constant refractive-index surfaces. It avoids the problem that the traditional tracing method cannot adapt to the area of sudden change in the refractive index and the area where the refractive index changes sharply. Therefore, a suitable distance can be performed in the iterative process. It can achieve high-efficiency and precise ray tracing in areas whether the refractive index changes slowly or sharply. According to the comparison of calculation examples, this method can achieve a tracing accuracy of 10−5 mm. The speed and precision of ray tracing are better than traditional methods.

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Huang, Chien Jung, Kuo Chien Liao, and Yan Kuin Su. "Structure Property of Titanium Dioxide Thin Films in Sintered Temperature by the Sol-Gel Method." Key Engineering Materials 368-372 (February 2008): 1465–67. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.1465.

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Titanium dioxide (TiO2) thin film on glass substrate is fabricated by sol-gel method. The TiO2 film is sintered at various temperatures for investigation on the refraction index and crystallization characteristic. The lower refractive index of the TiO2 thin film is 1.89 when the sintering is performed at the low temperature of 200°C and the thickness is 448 nm. However, the higher refractive index of 2.55 and chemical stability of the TiO2 film in rutile phase are obtained via sintering temperature at 700°C.

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Santran, Stephane, Miguel Martinez-Rosas, Lionel Canioni, Laurent Sarger, Larissa N. Glebova, Alan Tirpak, and Leonid B. Glebov. "Nonlinear refractive index of photo-thermo-refractive glass." Optical Materials 28, no. 4 (March 2006): 401–7. http://dx.doi.org/10.1016/j.optmat.2005.02.004.

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Gaudiana, Russell A., and Richard A. Minns. "High Refractive Index Polymers." Journal of Macromolecular Science: Part A - Chemistry 28, no. 9 (September 1991): 831–42. http://dx.doi.org/10.1080/00222339108054062.

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Rourke, Patrick M. C., Christof Gaiser, Bo Gao, Daniele Madonna Ripa, Michael R. Moldover, Laurent Pitre, and Robin J. Underwood. "Refractive-index gas thermometry." Metrologia 56, no. 3 (April 18, 2019): 032001. http://dx.doi.org/10.1088/1681-7575/ab0dbe.

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37

Padilla, Willie J., Dimitri N. Basov, and David R. Smith. "Negative refractive index metamaterials." Materials Today 9, no. 7-8 (July 2006): 28–35. http://dx.doi.org/10.1016/s1369-7021(06)71573-5.

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38

Yata, Junzo. "Refractive Index of Refrigerants." REVIEW OF HIGH PRESSURE SCIENCE AND TECHNOLOGY 3, no. 4 (1994): 332–35. http://dx.doi.org/10.4131/jshpreview.3.332.

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39

Siviter, J. P. "Refractive index without sines." Physics Education 29, no. 1 (January 1994): 51. http://dx.doi.org/10.1088/0031-9120/29/1/011.

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Veselago, Victor, Leonid Braginsky, Valery Shklover, and Christian Hafner. "Negative Refractive Index Materials." Journal of Computational and Theoretical Nanoscience 3, no. 2 (April 1, 2006): 189–218. http://dx.doi.org/10.1166/jctn.2006.3000.

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The main directions of studies of materials with negative index of refraction, also called left-handed or metamaterials, are reviewed. First, the physics of the phenomenon of negative refraction and the history of this scientific branch are outlined. Then recent results of studies of photonic crystals that exhibit negative refraction are discussed. In the third part numerical methods for the simulation of negative index material configurations and of metamaterials that exhibit negative index properties are presented. The advantages and the shortages of existing computer packages are analyzed. Finally, details of the fabrication of different kinds of metamaterials are given. This includes composite metamaterials, photonic crystals, and transmission line metamaterials for different wavelengths namely radio frequencies, microwaves, terahertz, infrared, and visible light. Furthermore, some examples of practical applications of metamaterials are presented.

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41

Ohnishi, K., M. Shiba, M. Yamakage, and Y. Kajikawa. "Refractive index of TlGaAs." physica status solidi (c) 5, no. 9 (July 2008): 2932–34. http://dx.doi.org/10.1002/pssc.200779204.

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Lv, Hao, Aimei Liu, Jufang Tong, Xunong Yi, Qianguang Li, Xinmin Wang, and Yaoming Ding. "Nondestructive measurement of refractive index profile of gradient refractive index rod lens." Review of Scientific Instruments 81, no. 10 (October 2010): 103104. http://dx.doi.org/10.1063/1.3492154.

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Lv, Hao, Aimei Liu, Xunong Yi, and Qianguang Li. "Fabrication and refractive index research on gradient refractive index (GRIN) hexagonal microlenses." Glass Technology: European Journal of Glass Science and Technology Part A 57, no. 3 (June 21, 2016): 101–4. http://dx.doi.org/10.13036/17533546.57.3.024.

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FUKUCHI, TETSUO, NORIKAZU FUSE, MAYA MIZUNO, and KAORI FUKUNAGA. "Measurement of Refractive Index of Thermal Barrier Coating Using Reflection of Terahertz Waves and Variable Aperture." Electronics and Communications in Japan 99, no. 5 (April 14, 2016): 54–61. http://dx.doi.org/10.1002/ecj.11812.

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SUMMARYA method to measure the refractive index of the ceramic layer of a thermal barrier coating (TBC) using the intensity ratio between the reflection of terahertz waves from the ceramic surface and a reference metal plate is proposed. This method uses a variable aperture to change the relative proportions of specular refraction and scattering from the ceramic surface. The refractive index is calculated based on the specular reflectivity, which is obtained from the intensity ratio when the field of view is extrapolated to zero. Measurement of a TBC specimen resulted in a refractive index of 4.7, which was in good agreement with the refractive index of the ceramic material obtained by terahertz time‐domain reflectometry. In addition, the surface roughness of the ceramic surface was obtained based on the frequency characteristics of the reflections from the ceramic surface and a reference metal plate. A surface roughness of 14 μm was obtained, which matched the results of microscopic observation of a TBC specimen whose coating was applied using the same lot as the specimen used in the measurement.

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Wang, Jian Gang, Hua Lin Wang, Yi Fan, and Yuan Huang. "The Index Matching Method and its Application in V3V Measurements." Advanced Materials Research 1051 (October 2014): 946–50. http://dx.doi.org/10.4028/www.scientific.net/amr.1051.946.

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In imaging measurements on the fluid flow, the quality of particle image is essential to the outcomes of the velocity field. The method to eliminate the problems of refraction and reflection is to match the refractive indices of the working fluid and the surrounding solid wall. In this article, a comprehensive summary of the refractive index matching method was presented. Three fluid materials, two organic and one non-organic was used to conduct index matching and their effect were compared. Results show the perfect index matching is effective to improve the measurement accuracy of imaging measurements.

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RUOFF, ARTHUR L., and KOUROS GHANDEHARI. "THE REFRACTIVE INDEX OF HYDROGEN AS A FUNCTION OF PRESSURE." Modern Physics Letters B 07, no. 13n14 (June 20, 1993): 907–11. http://dx.doi.org/10.1142/s0217984993000904.

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It is shown that the refractive index of hydrogen is given by n H 2 = 1 + 3.046 ρ + 2.6 ρ2 where ρ has units of mol/cm3. Here ρ at a given pressure, P, can be obtained from the equation of state, ρ(P). This relation is combined with that for the refractive index of loaded diamond anvils to obtain n H 2/n D vs P. This is found to be in good agreement with the ratio n H 2/nD measured directly at different pressures by Fabry-Perot interferometry. The density variation of the molar refraction is computed.

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Bohannon, Kevin P., Ronald W. Holz, and Daniel Axelrod. "Refractive Index Imaging of Cells with Variable-Angle Near-Total Internal Reflection (TIR) Microscopy." Microscopy and Microanalysis 23, no. 5 (September 18, 2017): 978–88. http://dx.doi.org/10.1017/s1431927617012570.

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AbstractThe refractive index in the interior of single cells affects the evanescent field depth in quantitative studies using total internal reflection (TIR) fluorescence, but often that index is not well known. We here present method to measure and spatially map the absolute index of refraction in a microscopic sample, by imaging a collimated light beam reflected from the substrate/buffer/cell interference at variable angles of incidence. Above the TIR critical angle (which is a strong function of refractive index), the reflection is 100%, but in the immediate sub-critical angle zone, the reflection intensity is a very strong ascending function of incidence angle. By analyzing the angular position of that edge at each location in the field of view, the local refractive index can be estimated. In addition, by analyzing the steepness of the edge, the distance-to-substrate can be determined. We apply the technique to liquid calibration samples, silica beads, cultured Chinese hamster ovary cells, and primary culture chromaffin cells. The optical technique suffers from decremented lateral resolution, scattering, and interference artifacts. However, it still provides reasonable results for both refractive index (~1.38) and for distance-to-substrate (~150 nm) for the cells, as well as a lateral resolution to about 1 µm.

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FENG, LIANG, XIAO-PING LIU, JIE REN, YAN-FENG CHEN, and YONG-YUAN ZHU. "COMPARISONS OF NEGATIVE REFRACTION IN LEFT-HANDED MATERIALS AND PHOTONIC CRYSTALS." International Journal of Modern Physics B 19, no. 23 (September 20, 2005): 3547–61. http://dx.doi.org/10.1142/s0217979205032371.

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Using the equifrequency surfaces (EFS) to describe negative refractions in left-handed materials (LHMs) and photonic crystals (PCs), negative phase and negative group refractive indexes in LHMs were compared with positive phase and negative group refractive indexes in PCs. The refractive indexes in PCs were dependent on frequencies and incident angles of electromagnetic wave, while indexes in LHMs were constant in the left-handed region. Furthermore, the phase compensating effect resulting from the negative phase refractive index was addressed to distinguish the perfect lens made of LHMs from the superlens realized in the all angle negative refraction (AANR) region of PCs.

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Shoar Ghaffari, S., and S. Makouei. "Liquid core photonic quasi-crystal fiber plasmonic refractive index sensor for wide refractive index detection range." Advanced Electromagnetics 11, no. 2 (August 6, 2022): 70–73. http://dx.doi.org/10.7716/aem.v11i2.1798.

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In this paper, a photonic quasi-crystal fiber plasmonic refractive index sensor is numerically analyzed. The fiber core is infiltrated with six hypothetical liquids, which refractive indices of them vary from 1.44 to 1.49. The reason for filling the core with different refractive index of liquids is that changeable refractive index of the core is an option to adjust the sensor performance at different intervals of analyte refractive index. Due to changes in the core refractive index, a large RI detection range from 1.38 to 1.53 is obtained and the sensor exhibits maximum spectral sensitivity of 10,000 nm/RIU. The properties of the sensor are calculated by the finite element method. The geometrical parameters of the sensor such as analyte height and gold thickness are also evaluated. The proposed sensor has a tunable capability which can be suitable for RI detection of biomedical liquid analytes in various ranges of refractive indices.

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Odintsov, S. L., V. A. Gladkikh, A. P. Kamardin, V. P. Mamyshev, and I. V. Nevzorova. "Estimates of the refractive index and regular refraction of optical waves in the atmospheric boundary layer. Part 1. Refractive index." Optika atmosfery i okeana 30, no. 10 (2017): 821–28. http://dx.doi.org/10.15372/aoo20171002.

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Journal articles on the topic 'Refractive index'

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