Field-controllable liquid-crystal phase grating

Hori, Yasuhiko; Asai, K.; Fukai, Masakazu

doi:10.1109/t-ed.1979.19678

Cited by 35 publications

(16 citation statements)

References 8 publications

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“…[1,2] No single material satisfies all these criteria. Except yttria-stabilized zirconia (YSZ), other possible TBC materials currently under investigation are zircon, [3,4] mullite, [5,6] CaO±SiO 2 and CaO±ZrO 2 , [7] silicates, [8] ) on a MCrAlY (M = Ni, Co) bond coat, deposited either by air-plasma spraying (APS) or by electron-beam physical vapor deposition (EB-PVD). [1] A major disadvantage of YSZ is the limited operation temperature (< 1200 C) for long-term applications.…”

Section: Methodsmentioning

confidence: 99%

“…For thermally treated films of chiral polyfluorene, g abs > 0.15 has been reported by Oda et al, [4] while for the poly(phenyleneethylene) values up to g abs = 0.38 have been found by Bunz and co-workers. [6] These g values are considerably higher than those reported for films of poly(thiophene), [7] poly(thienylenevinylene), [8] and poly(p-phenylenevinylene) (PPV) [9] Here, we study circular dichroism of fluorene homopolymer bearing chiral (S)-3,7-dimethyloctyl sidechains on the 9 position of the fluorene moiety (see Fig. 1).…”

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confidence: 96%

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The Chiroptical Properties of a Thermally Annealed Film of Chiral Substituted Polyfluorene Depend on Film Thickness

et al. 2003

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The synthesis of the azobenzene gelator has already been reported [10a]. To prepare a self-assembled cholesteric gel, a homogeneous mixture of BL006/ R811/gelator was obtained by first dissolving all compounds in a common solvent, tetrahydrofuran (THF), and then evaporating the solvent under reduced pressure. The mixture was flow-filled, at 130 C, into the 10 lm thick electrooptic cell, and subsequent fast cooling of the mixture to room temperature resulted in the gel sample with a uniform physical network built up from nanometer-sized hydrogen-bonded fibrous aggregates (Fig. 1a). To record a grating, a photomask was positioned on one side of the cell, and the whole was placed into a thermostat hot stage and heated to the recording temperature. A curing system (Novacure apparatus) was used to expose the sample to UV light centered at 360 nm. Once the irradiation was completed, the sample was cooled to room temperature, either under irradiation or with irradiation turned off. The gratings were observed on a polarizing optical microscope (Leitz DMR-P apparatus). For SEM observations of the aggregates, on a Hitachi S-4700 FEG SEM apparatus, the cell was carefully opened and the cholesteric LC host was extracted in hexane.For the measurements of the diffraction efficiency under an electric field, a He±Ne laser (633 nm) was used as the incident light source (normal to the cell) and the 1st order (+1) diffraction signal, I d , was monitored using a high-speed photodetector (Displaytech) collected to a digital oscilloscope (Tektronix, TDS 420 A apparatus). A high-voltage waveform generator (WFG500 apparatus, FLC Electronics) was used to apply the AC (1000 Hz), square wave, and pulse electric fields through the cell. The diffraction efficiency was calculated as the ratio of I d over the intensity of the laser beam before reaching the cell.

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Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 96%

The Chiroptical Properties of a Thermally Annealed Film of Chiral Substituted Polyfluorene Depend on Film Thickness

et al. 2003

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“…In the black region, the liquid crystal molecule was aligned parallel to the polarizer. Therefore, diffraction due to the periodic change of the refractive index 10) is the switching phenomenon of this case. Figure 14 shows the transmittance versus voltage characteristics of the twisted state.…”

Section: Transmittance Versus Voltage Characteristics and Itsmentioning

confidence: 98%

“…Much research has been conducted on nematic liquid crystal display (LCD) modes, e.g., dynamic scattering (DS), 1) twisted nematic (TN), 2) super twisted nematic, 3) guest-host, 4) electrically controlled birefringence, 5,6) nematic-cholesteric phase transition, 7,8) polymer-dispersed liquid crystal (PDLC), 9) diffraction, 10) in-plane switching, 11,12) bistable twisted nematic, 13) axially symmetric aligned microcell, 14) and multi-domain vertical alignment. 15) To date, a high contrast ratio, sufficient response speed and wide viewing angle have been realized along with the active matrix configuration.…”

Section: Introductionmentioning

confidence: 99%

Field Emission Microscope Observations of H₂- and Metal-Phthalocyanines

Morikawa¹,

Okamoto²

1996

Jpn. J. Appl. Phys.

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“…LC phase gratings are a polarization-independent alternative to the polarizationdependent LC modes discussed in the first part of this paper. Hori [16] proposed an LC grating design based on field-induced tunable birefringence. However, the untwisted device exhibited polarization-dependent performance and required a high voltage to achieve high contrast.…”

Section: Polarization-independent Lc Phase Gratingsmentioning

confidence: 99%

Nematic LC modes and LC phase gratings for reflective spatial light modulators

Yang

1998

IBM J. Res. & Dev.

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Single-domain nematic liquid crystal (LC) devices based on the polarization-rotation effect, the birefringent effect, or both have been investigated for reflective spatial light modulators (SLMs) which use a polarizing beam splitter to separate the input light beam from its orthogonal output beam. We have evaluated each LC mode in terms of its contrast ratio, optical efficiency, operating voltage, and tolerance to cell-gap nonuniformity. We studied the hybridaligned and the 0"-, 45°-, and 63.6°-twisted nematic LC modes, which can be operated either normally white (NW) or normally black (NB). We have also investigated the mixed twisted nematic (MTN) and self-compensated twisted nematic (SCTN) modes in NW and the tilted homeotropic mode in NB. Twodimensional simulations have also been carried out for both NW and NB modes implemented in active-matrix-driven reflective SLMs to elucidate the effect of fringe fields, which tend to generate disclination lines in high-field on-pixels adjacent to low-field off-pixels. Numerical examples are given to illustrate that, for the NB modes, the disclination lines occurring in the field-on bright state appear dark and reduce the optical efficiency. However, for the NW modes, the disclination lines occurring In the field-on dark states generate a light leakage which degrades the contrast ratio. To improve optical efficiency, we have also studied polarizationindependent LC phase gratings using patterned alignment with opposite twist angles for reflective SLMs. The basic equations for the diffracted and nondiffracted intensities have been derived. The device parameters, operating voltage, and optical efficiency are given for various cases with a twist angle equal to or less than 90°.

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Field-controllable liquid-crystal phase grating

Cited by 35 publications

References 8 publications

The Chiroptical Properties of a Thermally Annealed Film of Chiral Substituted Polyfluorene Depend on Film Thickness

The Chiroptical Properties of a Thermally Annealed Film of Chiral Substituted Polyfluorene Depend on Film Thickness

Field Emission Microscope Observations of H₂- and Metal-Phthalocyanines

Nematic LC modes and LC phase gratings for reflective spatial light modulators

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Field-controllable liquid-crystal phase grating

Cited by 35 publications

References 8 publications

The Chiroptical Properties of a Thermally Annealed Film of Chiral Substituted Polyfluorene Depend on Film Thickness

The Chiroptical Properties of a Thermally Annealed Film of Chiral Substituted Polyfluorene Depend on Film Thickness

Field Emission Microscope Observations of H2- and Metal-Phthalocyanines

Nematic LC modes and LC phase gratings for reflective spatial light modulators

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Field Emission Microscope Observations of H₂- and Metal-Phthalocyanines