• Title/Summary/Keyword: polarization dependence

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Holographic Demultiplexer with Low Polarization Dependence Loss using Photopolymer Diffraction Gratings

  • Lee, Kwon-Yeon;Jeung, Sang-Huek;Do, Due-Dung;Kim, Nam;An, Jun-Won
    • Journal of the Optical Society of Korea
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    • v.11 no.2
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    • pp.51-54
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    • 2007
  • A holographic demultiplexer aimed at producing low polarization dependence loss using a long period volumetric diffraction grating inside photopolymer has been reported and experimentally demonstrated. To obtain the long period gratings, two kinds of gratings are recorded by angle of $4^{\circ}\;and\;6^{\circ}$ corresponding to the polarization dependence property of below 0.5 dB. From the experimental results, we demonstrate the 0.8 nm-spaced 21 channel holographic demultiplexer with the polarization dependence loss of less than -0.38 dB, the channel uniformity of 0.495 dB, and the channel crosstalk of -13 dB.

Stress Profile Dependence of the Optical Properties in Strained Quantum Wire Arrays

  • Yi, Jong-Chang;Ji, Jeong-Beom
    • Journal of the Optical Society of Korea
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    • v.7 no.1
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    • pp.13-19
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    • 2003
  • The effects of strain distribution in quantum wire arrays have been analyzed using a finite-element method including both the hydrostatic and shear strain components. Their effects on the optical properties of the quantum wire arrays are assessed for various types of stress profiles by calculating the optical gain and the polarization dependence. The results show unique polarization dependency, which can be exploited either for the single polarization or the polarization-independent operation in quantum wire photonic devices.

Polarization-dependence of liquid crystal alignment on an organic surface with ion beam irradiation

  • Choi, Dae-Sub;Han, Jeong-Min
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.208-208
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    • 2009
  • We used Brewster's Law to examine the mechanism of liquid crystal (LC) alignment on an organic insulation layer when subjected to ion-beam irradiation. Brewster's Law implies that the maximum rate polarized ray on a slanted insulation layers on the substrate and it illustrates the dependence of polarization and themechanical structure on the ion beam irradiation process. The pretilt angle of nematic LCs on the organic insulation surface was about $1.13^{\circ}$ for an ion beam exposure of $45^{\circ}$ for 1 minute at 1800eV. This shows the dependence of LC alignment on the polarization ratio in a slanted organic insulation layer.

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Effect of Out-of-plane Retardation of Substrate Film on the Viewing-angle Dependence of Transmittance in a Display Device

  • Ahn, Sumin;Lee, Ji-Hoon
    • Current Optics and Photonics
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    • v.5 no.1
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    • pp.45-51
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    • 2021
  • The effect of the out-of-plane retardation (Rth) of a substrate film on the viewing-angle dependence of transmittance (TR) in a display device was investigated. When the polarization state of input light deviates from the transmission axis of the polarizer, Rth of the substrate film induces inhomogeneous viewing-angle dependence of TR. The inhomogeneity of TR gets worse for greater values of of Rth. The inhomogeneous TR profile can be eliminated by inserting compensation films, which convert the input polarization state to the linear polarization state parallel to the transmission axis of the polarizer.

The interface effects on polarization dependence of waveguide and the design of polarization independent 2 dimensional waveguide on InP for arrayed waveguide grating (도파로의 편광 의존성에 경계면이 미치는 효과와 편광 독립적인 InP형 배열 도파로 회절 격자 소자를 위한 2차원 광 도파로의 설계)

  • 김동철;최정훈;유건호;김형문;주흥로;김홍만
    • Korean Journal of Optics and Photonics
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    • v.9 no.5
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    • pp.307-314
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    • 1998
  • We have studied the effects of interface on polarization dependence of waveguide and designed the polarization independent 2-dimensional waveguides on InP for arrayed waveguide grating. To figure out the effects of interface on polarization dependence, we have solved the 1-dimensional wave equation using a transfer matrix method. It is shown that the birefringence becomes stronger as the number of interfaces increases. In order to design polarization independent 2-dimensional waveguides, we have used effective index method. The structures considered are ridge type, raised strip type, and buried type waveguide. In the cases of ridge and raised strip type, conventional effective index method was used. In the case of buried type corrected effective index method was used. We have determined the height and width of waveguides such that the waveguides become polarization independent.

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Influence of Electric Poling an Fracture Toughness of Ferroelectric-Ferroelastic PZT Ceramics

  • Zuokai Ke;Sunggi Baik
    • The Korean Journal of Ceramics
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    • v.1 no.4
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    • pp.197-203
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    • 1995
  • Nearly fully dense PZT samples both with tetragonal and with morphotropic phase boundary compositions were prepared by the conventional powder processing and sintering. A micro-indentation technique was used to evaluate the dependence of fracture toughness on remanent polarization, crack length and the direction of crack propagation. The result shows that the toughness increases with the remanent polarization along the poling direction and decreases in the transverse direction. The dependence of toughness on the remanent polarization is neither symmetric nor linear but rather shown to be saturated quickly with the increase in remanent polariztion. R-curve behaviors are observed in both poled and unpoled samples. Sequential SEM and XRD studies on annealed, poled, ground, fractured and etched samples show that domain switching is evident as a viable toughening mechanism but might depend upon the rate of crack propagation. Grain bridging is also observed as one of the active toughening mechanisms.

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Dependence of Retardation Dispersion on the Ultraviolet Polarization Direction During Photopolymerization of Self-organized Smectic Reactive Mesogen Molecules

  • Jeong, Jinyoung;Choi, Yu-Jin;Jeong, Kwang-Un;Lee, Ji-Hoon
    • Current Optics and Photonics
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    • v.2 no.3
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    • pp.286-290
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    • 2018
  • We investigated the dependence of the retardation dispersion on the polarization direction of ultraviolet (UV) light during the photopolymerization of self-organized smectic reactive mesogen (RM) molecules. RM retarder film that was photopolymerized with UV light linearly polarized parallel to the layer plane showed negative dispersion (ND) of retardation for a wide range of UV polymerization temperatures. On the other hand, film that was photopolymerized with unpolarized UV light showed negative dispersion in a narrow range of UV polymerization temperatures. With a certain UV polymerization temperature, the dispersion of retardation was converted from positive to negative, depending on the UV polarization.

Characterization of wavelength dependent birefringence inside the ring type liber cavity using the polarization dependence of laser Outputs

  • Kim, Ho-Young;Kang, Kwang-Yong;Kim, Kyoung-Hon
    • Journal of the Optical Society of Korea
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    • v.6 no.2
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    • pp.37-43
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    • 2002
  • Using the polarization dependence of laser output powers, we measured the characteristics of the birefringence, such as the magnitude of phase retardation, the ellipticity, and the off axis angle to the fiber optical axis, inside the ring type fiber laser cavity.

Suppression of polarization effects in Er-doped fiber source for gyroscope by polarization scrambling (자이로용 Er-첨가 광섬유 광원에서 편광 스크램블링을 이용한 편광효과의 억제)

  • 김택중;진영준;박희갑
    • Korean Journal of Optics and Photonics
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    • v.14 no.4
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    • pp.449-453
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    • 2003
  • In a broadband erbium-doped fiber source for fiber optic gyroscope, a pump-polarization scrambling scheme is used to suppress the polarization dependence of the source mean wavelength. The degree of polarization of the pump is reduced to 1.4% by applying proper modulation depth to the polarization modulator where 10 m-long single-mode fiber is wound on a cylindrical PZT. In the case of using the pump-polarization scrambler as well as the output depolarizer, the mean-wavelength variations due to the random change of polarization are measured to be less than our measurement limit of 5 ppm.

Study of Liquid Crystal Alignment and Polarization-dependence on organic surface with slanted ion beam irradiation (유기절연막으로의 경사진 이온빔조사가 유기막 표면에서의 편광발생과 액정배향에 미치는 영향에 관한 연구)

  • Han, Jeong-Min;Choi, Dae-Sub;Hwang, Jong-Sun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.03b
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    • pp.15-16
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    • 2010
  • We used Brewster's Law to examine the mechanism of liquid crystal (LC) alignment on an organic insulation layer when subjected to ion-beam irradiation. Brewster's Law implies that the maximum rate polarized rayon a slanted insulation layers on the substrate and it illustrates the dependence of polarization and themechanical structure on the ion beam irradiation process. The pretilt angle of nematic LCs on the organic insulation surface was about $1.13^{\circ}$ for an ion beam exposure of $45^{\circ}$ for 1 minute at 1800eV. This shows the dependence of LC alignment on the polarization ratio in a slanted organic insulation layer. We also discussed the electro-optical characteristic of twisted nematic (TN) LCD using ion beam irradiation on organic overcoat layer.

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