• 제목/요약/키워드: quarter-wave-plate film

검색결과 3건 처리시간 0.024초

Ultra Thin Reflective Flexible Liquid Crystal Display

  • Liu, Kang-Hung;Kuo, Chia-Wei;Ku, Chun-Kang;Chang, Chih-Yuan;Liao, Chi-Chang
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1080-1082
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    • 2008
  • An ultra-thin reflective flexible LCD film has been demonstrated. The 30% thickness of the display can be reduced by applying a quarter-wave-plate film as upper substrate. A low temperature alignment material and special designed photo spacer were applied in this new display. The bending behavior was improved by reduced thickness.

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Polarization Phase-shifting Technique for the Determination of a Transparent Thin Film's Thickness Using a Modified Sagnac Interferometer

  • Kaewon, Rapeepan;Pawong, Chutchai;Chitaree, Ratchapak;Bhatranand, Apichai
    • Current Optics and Photonics
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    • 제2권5호
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    • pp.474-481
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    • 2018
  • We propose a polarization phase-shifting technique to investigate the thickness of $Ta_2O_5$ thin films deposited on BK7 substrates, using a modified Sagnac interferometer. Incident light is split by a polarizing beam splitter into two orthogonal linearly polarized beams traveling in opposite directions, and a quarter-wave plate is inserted into the common path to create an unbalanced phase condition. The linearly polarized light beams are transformed into two circularly polarized beams by transmission through a quarter-wave plate placed at the output of the interferometer. The proposed setup, therefore, yields rotating polarized light that can be used to extract a relative phase via the self-reference system. A thin-film sample inserted into the cyclic path modifies the output signal, in terms of the phase retardation. This technique utilizes three phase-shifted intensities to evaluate the phase retardation via simple signal processing, without manual adjustment of the output polarizer, which subsequently allows the thin film's thickness to be determined. Experimental results show that the thicknesses obtained from the proposed setup are in good agreement with those acquired by a field-emission scanning electron microscope and a spectroscopic ellipsometer. Thus, the proposed interferometric arrangement can be utilized reliably for non-contact thickness measurements of transparent thin films and characterization of optical devices.

Analysis of compensation principle for wide viewing angle characteristics of an OCB cell by the $Poincar\acute{e}$ sphere representation

  • Lee, Seong-Ryong;Yoon, Tae-Hoon;Kim, Jae-Chang
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.167-170
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    • 2006
  • In this paper, we study how the viewing angle characteristics of a bend cell can be compensated by uniaxial films such as positive a-plate, negative c-plate and circular polarizer. Especially, it is confirmed how the circular polarizer composed of a quarter-wave plate and a linear polarizer enhances the viewing angle characteristics by the $Poincar\acute{e}$ sphere representation. Also, additional compensation film is designed to improve the viewing angle characteristics of the cell by the $Poincar\acute{e}$ sphere representation.

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