• Journal of the Optical Society of Korea
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• v.19 no.5
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• pp.449-455
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• 2015

In this study we propose a new photonic crystal fiber (PCF) design that simultaneously offers broadband single-mode operation, high birefringence, and large normal dispersion in the optical-communication wavelength regime. The waveguide is based on a hybrid square-lattice PCF (HS-PCF) that has circular air holes of two different diameters alternating in the cladding, plus a pure silica defect at the center. The optical properties of the guided modes are analyzed numerically by the finite-element method (FEM) with a perfectly matched layer as the boundary condition. The optimized HS-PCF has a dispersion coefficient of $-601.67\;ps\;nm^{-1}\;km^{-1}$ and a high birefringence of $1.025{\times}10^{-2}$ at $1.55{\mu}m$. In addition, over the S+C+L+U wavelength bands the proposed HS-PCF with ultraflat birefringence with a slope on the order of $10^{-5}$.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.4
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• pp.631-636
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• 2002

It is necessary to improve mechanical and optical properties in the optical disk substrates as the information storage devices with high storage density using blue laser are being developed. Injection compression molding is regarded as the most suitable process to manufacture optical disk substrates for quality recording and read-out. In the present research, the effects of mold temperature and the insulation layer thickness on gapwise birefringence and the land-groove pattern were investigated. It was found that the values of the birefringence distribution were very sensitive to mold temperature history, and the level of birefringence reduced and, furthermore, the quality of replication was improved due to the insulation layer.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1135-1137
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• 2008

In this paper, it is proposed that the integral imaging technique is applied to reconstruct 3D (three dimensional) objects with enhanced depth of field, computationally and optically. Lens array using birefringence material is adopted to obtain the reconstruction. The elemental images sets are picked up through common micro lens array and utilized to present 3D reconstruction images using adopted lens array.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.260-262
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• 2003

We report several difluoro isothiocyanato tolane-based liquid crystal (LC) singles having a high optical birefringence. Several eutectic mixtures are formulatd using these LC singles exhibiting a wide nematic phase range and high birefringence. We will report the physical properties of and photochemical stability of these new eutectic mixtures.

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.274-275
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• 2009

An integral imaging system resorting to multiple birefringence lens arrays using Jones Matrix was analyzed and implemented. Each birefringence lens array was produced by placing a liquid crystal layer on a conventional lens array. Its depth of field was proved to be extended theoretically.

• Transactions of Materials Processing
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• v.13 no.2
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• pp.180-187
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• 2004

A computer code was developed to simulate the filling stage of the injection/compression molding process by a finite element method. The constitutive equation used here was the compressible Leonov model. The PVT relationship was assumed to follow the Tait equation. The flow-induced birefringence was related to the calculated flow stresses through the linear stress-optical law. Simulations of a disk part under different process conditions including the variation of compression stroke and compression speed were carried out to understand their effects on birefringence variation. The simulated results were also compared with those by conventional injection molding.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.446-449
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• 2005

The alignment property of liquid crystals on the two-easy axes substrate is investigated. The two-easy axes substrate frustrates the orientation of the LCs next to the substrate, and hence influences the birefringence of the LC cell. Experimental findings reveal that the ratio of the rubbing strengths in the different rubbing directions and the cell thickness substantially influence the birefringence of the LC cell. The surface anchoring energetic competition between the different rubbing directions contributes to the observed results.

• ETRI Journal
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• v.34 no.6
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• pp.946-949
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• 2012

We present the optimization of a birefringence-enhanced-waveguide (BWG)-based polarization beam splitter (PBS) in a Mach-Zehnder interferometer (MZI) configuration and analyze the structure-dependent or polarization-dependent phase difference, using a delay-line MZI (DL-MZI). We fabricate the DL-MZI using silica-based planar lightwave circuit technology and, using the DL-MZI, demonstrate the ability to optimize a PBS by measuring the birefringence of the BWG and structure-dependent phase offset.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.1
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• pp.66-72
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• 2007

A computer code was developed to simulate the filling stage of an injection/compression molding process using a finite element method. The constitutive equation was the compressible Leonov model and the PVT relationship was assumed to follow the Tait equation. The flow-induced birefringence was related to the calculated flow stresses through the linear stress-optical law. Simulations of a disk under different processing conditions, including variations of the compression stroke and compression speed, were performed to determine their effects on the flow-induced birefringence. Simulated pressure traces were also compared to those obtained in conventional injection molding and with experimental data from the literature.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.1
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• pp.58-63
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• 2001

We have investigated the photoinduced birefrinence by the electric field effects in chalcogenide thin films. The electric field effects have investigated the various applied bias voltages(forward and reverse) in chalcogenide thin films. A pumping (inducing) and a probing bean were using a linearly polarized He-Ne laser light (633nm) and semiconductor laser light (780nm), respectively. The result was shown that the birefringence had a higher value in DC +2V than the others, Also, we obtained the birefringence in the electric field effects by various voltages. In addition, we have discussed the anisotropy property of chalcogenide thin films by the electric field effects.