• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.195-195
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• 2010

In recent years, Anodic aluminum oxide(AAO) has become popular and attractive materials. It can be easily fabricated and self-organized pore structures. It has been widely used as a biosensor membrane, photonic crystal for optical circuit and template for nanotube growth etc. In previous papers, the theory was developed that AAO shows anisotropic optical properties, since it has anisotropic structure with numerous cylindrical pores. It gives rise to the anisotropy of the refractive index called as birefringence. It can be used as conventional polarizing elements with high efficiency and low cost. Therefore, we would like to compare the theory and experimental results in this study. One method which can measure effective refractive index of thin film is the prism coupling technique. It can give accurate results fast and simply. Furthermore, we can also measure separately the refractive index with different polarization using polarization of the laser (TE mode and TM mode). We calculated the effective refractive index with effective medium approximations (EMAs) by pore size in the SEM image. EMAs are physical models that describe the macroscopic system as the homogeneous and typical method of all mean field theories.

• Journal of the Korean Chemical Society
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• v.55 no.1
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• pp.141-146
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• 2011

• Korean Chemical Engineering Research
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• v.45 no.4
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• pp.335-339
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• 2007

In order to overcome the problem of poor hardness of transparent polycarbonate (PC) sheets, organic-inorganic hybrid hard coating solutions, which show a high refractive index above 1.58, were made by the sol-gel method. These hybrid coating solutions were obtained from mixture of titanium tetraisopropoxide (TTIP), and (3-glycidoxypropyl)trimethoxysilane (GPTMS). The PC sheets were spin-coated, and cured at $120^{\circ}C$ for 2 hr. Change of refractive index in the range of 1.53-1.61 was obtained by varying the GPTMS content. The refractive index of the coated film decreased with increasing the GPTMS content, while the pencil hardness of the coated film was found to increase with increasing the GPTMS content.

• Korean Journal of Optics and Photonics
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• v.20 no.2
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• pp.81-86
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• 2009

Digital holography and refractive index difference are used to measure a high aspect ratio's patterns. When interference fringes are very closely spaced, the phase data containing high frequencies where $2{\pi}$ ambiguities cannot be resolved. In this technique, the optical path difference is decreased by decreasing the refractive index difference. As a result, we solve the $2{pi}$ ambiguities. Also, this technique is applicable to measure the refractive index if the shape of the sample is known.

• Korean Journal of Materials Research
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• v.27 no.1
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• pp.1-7
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• 2017

Zirconia nanoparticles were widely used as filler in order to get high refractive index layer. However, dispersion of nanoparticles is difficult due to their agglomeration in solvent. In this study, the dispersibility of the zirconia suspension is promoted by controlling the steric hindrance and electrostatic interactions through the adsorption of PEI according to alkali treatment time. Also, to induce improved dispersibility on suspension, we changed the dispersion conditions variously and fabricated an ink formulation method for the coating layer. Zirconia suspension was characterized by dynamic light scattering (DLS), Zeta potential measurement, Transmission Electron Microscope (TEM) and FT-IR. We were able to confirm that good dispersion of zirconia suspension by alkali treatment and PEI led to high refractive index.

• Journal of Sensor Science and Technology
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• v.17 no.4
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• pp.261-266
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• 2008

In this paper, we present thermal characteristics of high-temperature measurement sensor using fiber Bragg grating(FBG), including peak reflectivity, FWHM bandwidth and various normalized refractive index change along temperature variation. The temperature stability of FBG temperature sensor can be changed by varying the refractive index change and grating length. The proposed FBG temperature sensor can measure up to about $600^{\circ}C$ and 1000 hours of heating time.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.282-282
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• 2006

Nanoporous organosilicate thin films were realized by the microphase separation of pore generating components mixed with an organosilicate matrix. The refractive index of such nanoporous organosilicate films can be tuned in the range of $1.40{\sim}1.22$. With a nanoporous single layer with n ${\sim}1.225,\;99.85\;%$ transmittance in the visible range was achieved. In order to overcome the limitation on the narrow wavelength for high transmittance imposed by single nanoporous thin films, bilayer thin films with different reflectance for each layer were prepared by inserting high refractive index layer with a refractive index of 1.447. It is demonstrated that the novel broadband antireflection coating with improved transmittance can be easily achieved by the nanoporous bilayer thin films described in present study.

• Bulletin of the Korean Chemical Society
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• v.34 no.4
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• pp.1077-1080
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• 2013

Fluorinated polymaleimides with high thermal stability and low optical absorption loss in the optical communication wavelength of $1.55{\mu}m$ were investigated for application in low-loss waveguide materials. The fluorinated polymaleimides were prepared from two monomers phenylmaleimide (H-PMI) and pentafluorophenylmaleimide (F-PMI). All synthesized copolymers had high thermal stability (decomposition temperature $(T_d)=380-430^{\circ}C$). The refractive index of the copolymers could be tuned from 1.4969 to 1.5950 in the TE mode and from 1.4993 to 1.5932 for the TM mode at 632.8 nm by copolymerizing different weight ratios of H-PMI and F-PMI. The refractive index of the copolymers decreased with increasing F-PMI content. In addition, when the amount of F-PMI was increased, optical loss and absorption loss at 632.8 nm and 1550 nm, respectively, decreased.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.1-6
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• 2008

Purpose: Plastic optical monomer materials having ultra high refractive index have an income of the whole quantity from advanced nations to domestic companies which are related to plastic optical lens. It is necessary to develop novel plastic optical lens materials in order to overcome a FTA provision and revitalize a stagnating optical lens industry in the interior optical lens industries. The new plastic optical lens materials against the substitution effect of income should be gradually demanded. This work will be synthesized novel super high refractive monomer resin materials of urethane lens series and studied the properties of optical lens using it. Methods: ETS-4 (2-(2-mercaptoethylthio)-3-{2-[3-mercapto-2-(2-mercaptoethylthio)propyl thio]ethylthio}propane -1-thiol), which is optical lens monomer resin having super high refractive index, was synthesized and identified its structure and property by elemental analysis, EI-MS, TGA, FT-IR spectroscopy, $^1H$ and $^{13}C$ NMR spectroscopies. After mixing evenly from mixed monomer resin and diisocyanate series, it was casting in glass mold. After thermal curing, the obtained optical lenses were measured and compared with the refractive index and Abbe number for studies of their optical properties. Results: We have synthesized the novel ultra high refractive index monomer resin, ETS-4, and have identified its structure and property by elemental analysis, EI-MS, TGA, FT-IR spectroscopy, $^1H$ and $^{13}C$ NMR spectroscopies. The existence of three isomers for EST-4 was identified by $^{13}C$ NMR spectroscopy. The refractive index ($N_d$ at $25^{\circ}C$) of monomer resin in liquid state obtained from the Abbe refractometer was 1.647. The refractive indexes of raw plastic optical lenses prepared from the mixed ETS-4 monomer and diisocyanate series were in the range of 1.656~1.680. Conclusions: Novel super high refractive index plastic optical lens monomer was synthesized and analysed, the optical lenses prepared using it were colorless transparency and excellent properties. It is of utility for the industrialization.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.483-484
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• 2008

In this paper, we present high-temperature characteristics of tunable all-optic filter using fiber Bragg grating(FBG), including peak reflectivity, FWHM bandwidth, refractive index change along temperature variation. The characteristics of a FBG tunable filter with refractive index change is affected by its thermal stability.