• Title/Summary/Keyword: Spatial Modulator

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Polarimetric Measurement of Jones Matrix of a Twisted Nematic Liquid Crystal Spatial Light Modulator

  • Khos-Ochir, Tsogvoo;Munkhbaatar, Purevdorj;Yang, Byung Kwan;Kim, Hyun Woo;Kim, Jin Seung;Kim, Myung-Whun
    • Journal of the Optical Society of Korea
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    • v.16 no.4
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    • pp.443-448
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    • 2012
  • A polarimetric experimental method was developed to determine the Jones matrix elements of transparent optical materials without sign ambiguity. A set of polarization dependent transmittance data of the samples was measured with polarizer - sample - analyzer system and another set of data was measured with polarizer - sample - quarter-wave plate - analyzer. Two data sets were compared and mathematically analyzed to obtain the correct signs of the elements of the matrix. The Jones matrix elements of a quarter-wave plate were determined to check the validity of the method. The experimentally obtained matrix elements of the quarter-wave plate were consistent with the theoretical expectations. The same method was applied to obtain the Jones matrix elements of a twisted nematic liquid crystal panel.

Review of Liquid Crystal Spatial Light Modulators at Thales Research & Technology;Technology and Applications

  • Lee, Mane-Si Laure;Loiseaux, Brigitte;Dolfi, Daniel;Tonda, Sylvie;Huignard, Jean-Pierre
    • Journal of Information Display
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    • v.3 no.3
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    • pp.24-29
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    • 2002
  • Liquid Crystal Spatial Light Modulators (LC-SLMs) provide many interesting applications in laser optics and opto-el ectronic systems, in addition to displays. Among them, three topics developed at Thales Research & Technology are reviewed: wavefront correction for laser beam control, microwave processing in radar systems and holography for TN-LCDs viewing angle compensation.

BPM Design Optimization of Mach-Zehnder Type Tandem Optical Switch and Its Operational Characteristics (2단 종속 접속 마하젠더형 광스위치의 BPM 최적설계 및 동작특성)

  • Choi, Young-Kyu;Kim, Gi-Rae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.10
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    • pp.1829-1834
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    • 2008
  • An optical switch/modulator is designed and the light propagating characteristics is analyzed by the simplified BPM. The distinctive feature of the switch/modulator is that all the waveguide branches are designed to be single-mode. Principle of the device is based on the coupled mode theory in the Y-junction interconnecting waveguide. In spite of all the waveguides are designed to be single-mode, adjusting the interconnecting waveguide length of the device, the same characteristics as existing device up to date is obtainable. Numerical results show that the switching characteristics periodically depends on the interconnecting waveguide length with a spatial of about 150${\mu}m$ in the Ti:LiNbO3 step index waveguide. The concept of design would be utilized effectively in fabricating the monolithic high density of optical integrated circuit.

Evolution of spatial light modulator for high-definition digital holography

  • Choi, Ji Hun;Pi, Jae-Eun;Hwang, Chi-Young;Yang, Jong-Heon;Kim, Yong-Hae;Kim, Gi Heon;Kim, Hee-Ok;Choi, Kyunghee;Kim, Jinwoong;Hwang, Chi-Sun
    • ETRI Journal
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    • v.41 no.1
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    • pp.23-31
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    • 2019
  • Since the late 20th century, there has been rapid development in the display industry. Only 30 years ago, we used big cathode ray tube displays with poor resolution, but now most people use televisions or smartphones with very high-quality displays. People now want images that are more realistic, beyond the two-dimensional images that exist on the flat screen, and digital holography-one of the next-generation displaysis expected to meet that need. The most important parameter that determines the performance of a digital hologram is the pixel pitch. The smaller the pixel pitch, the higher the level of hologram implementation possible. In this study, we fabricated the world-smallest $3-{\mu}m$-pixel-pitch holographic backplane based on the spatial light modulator technology. This panel could display images with a viewing angle of more than $10^{\circ}$. Furthermore, a comparative study was conducted on the fabrication processes and the corresponding holographic results from the large to the small pixel-pitch panels.

Magnet Gear with Two-Axial Magnetic Paths (이축 방향의 복합 자기 경로를 갖는 마그네트 기어)

  • Kim, Moon Su;Jung, Kwang Suk
    • Journal of the Korean Society for Precision Engineering
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    • v.31 no.6
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    • pp.543-550
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    • 2014
  • A magnet gear composed of two layers of permanent magnets repeated circumferentially can transmit the power without mechanical contact. In the topology called by the magnet shutter gear known as the most competitive concept among the existing concepts, the number of pole-pairs on the high speed rotor corresponds to that of low speed rotor through electric steel set functioning as a magnetic modulator. The methodology is classified into radial type and axial type according to its magnetic path as in the motor. However, the magnetic modulator has multiple poles located separately. So, it is very complicated to assemble each module of the magnet gear mechanically and to sustain a mechanical stiffness of the modulator. The practical trouble can be solved partially through reconfiguring the modules. This paper deals with the novel magnetic shutter gear topology varying the magnetic path and its effectiveness is verified through real hardware implementation.