Session Index

S7. Display and Solid State Lighting

Display and Solid State Lighting V
Saturday, Dec. 2, 2023  16:00-17:00
Presider: Prof. Jia-De Lin (National Dong Hwa University, Taiwan)
Room: 92277 (2F)
16:00 - 16:15
Manuscript ID.  1079
Paper No.  2023-SAT-S0705-O001
Sergiy Valyukh Highly Energy Efficient LCDs
Sergiy Valyukh, Kenneth Järrendahl, Linköping University (Sweden)

The lighting efficiency of conventional liquid crystal displays (LCDs) usually does not exceed 8-10% for a white screen and 4-5% when the screen image consists of equal numbers of bright and dark pixels. The present work is devoted to development of LCDs utilizing light recycling and multilayered birefringent structures acting as non-absorbing polarizing color filters. An analysis of the characteristics of such a LCD versus parameters of the color filters is carried out. We demonstrate that it is possible to reach the lighting efficiency up to 75% at contrast ratio 20:1 for any numbers of bright and dark pixels.

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16:15 - 16:30
Manuscript ID.  0115
Paper No.  2023-SAT-S0705-O002
Tien-Hung Peng A smart window that uses dye-doped cholesteric liquid crystal as an electrically tunable thermoresponsive optic switch
Yi-Cheng Chang, Tien-Hung Peng, Sheng-Hsiung Yang, Institute of Lighting and Energy Photonics (Taiwan); Wei Lee, Institute of Imaging and Biomedical Photonics (Taiwan)

We developed an electrically controlled and thermally responsive cholesteric liquid crystal (CLC) smart window that transitions from high transmission to low transmission state as the temperature increases, functioning as a tunable thermo-optic switch. This device combines thermoresponsive chiral dopants, a dichroic dye, and a nematic liquid crystal (LC) to create a thermosensitive CLC. As the temperature changes, the thickness/pitch ratio of the CLC bulk varies, and combined with the absorption characteristic of the dispersed dichroic dye, it creates transparent and opaque optical states. This passive mechanism requires no additional energy, resulting in energy efficiency, and can be enhanced by actively

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16:30 - 16:45
Manuscript ID.  0249
Paper No.  2023-SAT-S0705-O003
Ching-Han Yang Active planar chiro-optic devices with broadband tunability and invertible chirality
Ching-Han Yang, Pei-Ru Song, Chia-Rong Lee, National Cheng Kung University (Taiwan)

Photon-based communication has the potential to significantly expand information capacity due to its multi-dimensional properties. In this study, we utilized the photo-alignment technique to fabricate various geometrical phase elements doped with photo-responsive molecular motors. When the incident light's wavelength falls within the bandgaps of cholesteric liquid crystals (CLCs), the reflected light acquires geometrical phases depending on the morphology of the micro-patterned CLCs on the substrate. By controlling the concentrations of molecular motors with opposite handedness, we can tune both the working bands and polarization handedness of the reflected beams, resulting in a high degree of freedom in tailoring light’s properties.

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16:45 - 17:00
Manuscript ID.  0118
Paper No.  2023-SAT-S0705-O004
Pei-Ching Wei Thermally adaptive polymer-stabilized cholesteric texture windows without surface orientation treatment
Yu-Xian Lin, Institute of Imaging and Biomedical Photonics (Taiwan); Pei-Ching Wei, Institute of Photonics System (Taiwan); Wei Lee, Institute of Imaging and Biomedical Photonics (Taiwan); Guan-Fu Sung, College of Photonics (Taiwan)

We propose a novel self-adaptive switchable device of a thermally responsive polymer-stabilized liquid crystal (LC) that alters transmittance levels based on the SmA–N* phase transition. Through photopolymerization subject to a curing voltage, a polymer network is formed to create the homeotropic configuration of the SmA phase in a cell, eliminating the need for an alignment layer. As the temperature rises, the LC bulk transforms to a disordered N* texture. The SmA–N* phase transition enables reversible self-switching of the polymer-stabilized cholesteric LC cell between the transparent and haze states. The proposed device presents a promising avenue for advanced technologies in

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