Polarizers/Polarization photo-patterned polarizer

A self-assembled monolayer of 4-cyano-4 -(10-thiodecoxy)stilbene on a Au-electrode was shown to have different hydrophobicities. In the trans-(18a) and cis- (18b) isomeric states (Figure 7.25). When the monolayer is in the CIS-State (18b), the polar cyano-groups are hidden in the monolayer and the hydrophobic spacers are exposed to the solution, thus providing the hydrophobic properties of the interface. After irradiation of the monolayer (X > 350 nm), the ds-stilbene units are photoisomerized to the fmws-state (18a), and the polar cyano-groups are mainly exposed to the solution. In this case, the interface becomes more hydrophilic, and the monolayer displays markedly different wetting properties. This difference allows the photo-patterning of the surface. ... 

Photo-patterned LLC i isotropic polarizer after evaporation state... 

Figure 4.21 LLC photoalignment left, by mechanical shear stress [60] right, by photoalignment [61]. Reproduced from V. M. Kozenkov, W. C. Yip, S. T. Tang, V. G. Chigrinov, and H.-S. Kwok, Thin photo-patterned internal polarizers for LCDs. SID OO Digest, p. 1099 (2000), The Society for Information Display...

Figure 5.6 Polarized transmission spectra of a photoaligned lyotropic LC polarizer. Tp and Ts represent the transmission spectra parallel and perpendicular to the direction of the polarized UV light respectively [7]. Reproduced from W. C. Yip, H.-S. Kwok, V. M. Kozenkov, and V. G. Chigrinov, Photo-patterned e-wave polarizer. Displays 22, 27 (2001), Elsevier...

Figure 5.15 Multifunctional polarizer (upper), comprising a linear polarizer (1) and a photo-patterned phase retarder (2), and its image (lower) in crossed polarizers [17, 18]. UV-irradiated (He-Cd laser, X = 325 nm) PVCN film (2), used for the photo-patterned phase retarder has a thickness of 10-40 xm. The variation of the optical axis of the phase retarder (3, 4) was done by changing the direction of the polarization of the activated UV illumination. Reproduced from [17, 18], Institute of Physics Publishing, Bristol and Philadelphia, 201-244 (2003)...

Figure 5.18 New possibility to obtain a color TN- or STN-LCD, using a photo-patterned retarder [18], Upper basic red, green, and blue colors obtained by the corresponding properly adjusted phase retarders (PRl, PR2, and PR3). Lower one of the possible configurations with TN-LCD, three polarizers (PiUPsjUPs, and double phase retarder (DPR) configuration comprising two phase retarders PRl and PR2, placed at symmetrical angles a with respect to the input (output) polarizer P1HP3. Reproduced from [18], Institute of Physics Publishing, Bristol and Philadelphia, 201-244 (2003)...

Transflective LCD ifh Photo-patterned Polarizers and Phase Retarders... 

This invention relates to methods for preparing photo-patterned mono- or polychromatic, polarizing films. The polarizer can be pixelated into a number of small regions wherein some of the regions have one orientation of the principal neutral or color absorbing axis and some other of the said regions have another orientation of the principal neutral or color absorbing axis. The axis orientation is determined by the polarization vector of actinic radiation and the multi-axes orientation is possible by a separated masked exposure. This polarizer can be placed on the interior substrate surface of the LCD cell. 

Figure 5.33 Spatial views of angle-resolved intensity patterns for the coincident emission of 4d5/2 photo- and N5-02>302 3 S0 Auger electrons in xenon caused by linearly polarized photons of 94.5 eV (electric field vector along the x-axis). (a) Fixed position of the photoelectron (e,) with (i) 0 = 90°, = 180° and (ii) 0 = 90°,

Appropriate modification of the ESR spectrometer and generation of free radicals by flash photolysis enables time-resolved (TR) ESR spectroscopy [22]. Spectra observed under these conditions are remarkable for their signal directions and intensities. They can be enhanced as much as one-hundredfold and appear as absorption, emission, or a combination of both. Effects of this type are a result of chemically induced dynamic electron polarization (CIDEP) these spectra indicate the intermediacy of radicals whose sublevel populations deviate substantially from equilibrium populations. Significantly, the splitting pattern characteristic of the spin-density distribution of the intermediate remains unaffected thus, the CIDEP enhancement not only facilitates the detection of short-lived radicals at low concentrations, but also aids their identification. Time-resolved ESR techniques cannot be expected to be of much use for electron-transfer reactions from alkanes, because their oxidation potentials are prohibitively high. Even branched alkanes have oxidation potentials well above the excited-state reduction potential of typical photo-... 

In order to produce surface-relief electro-optic gratings, Munakata et compared two fabrication methods of SRG inscription. In the first, the SRG was produced with an interference pattern of cw laser, with relatively modest intensities. The gratings so recorded were photo- and thermally erasable, and efficient writing was polarization dependent. In the second method, a phase mask was employed to provide the periodic intensity modulation of a pulsed laser, the 3rd-order harmonic (at 355 nm) of a Nd YAG laser. The SRG was produced with a single laser pulse, allowing a very short fabrication time (less than Is). The direshold for ablation was 500 mj/(em pulse), and the amplitude of the SRG increased with pulse energy. A depth of up to 300 rim could be achieved, leading to a smooth but not sinusoidal surface modulation. 

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