| 146. | One- and two-dimensional anisotropic diffractive gratings formed by periodic orthogonal molecular alignment in a hydrogen-bonded liquid crystalline polymer, A. Emoto, S. Manabe, T. Shioda, H. Ono, and N. Kawatsuki, J. Appl. Phys. 105 (2009) 103514. |
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Abstract |
| Anisotropic diffractive gratings having periodic orthogonal molecular alignments are formed by a linearly-polarized ultraviolet (LPUV) exposure through a photomask in hydrogen (H)-bonding liquid crystalline polymers (H-LCPs) using a unique molecular reorientation behavior. H-bonded side-chain groups of H-LCPs play an important role in the molecular reorientation and the resultant optical anisotropy originating from an intermolecular network composition. To evaluate its potential for optical applications, one- and two-dimensional diffractive gratings were fabricated and analyzed by both polarization optical microscopy (POM) and diffraction characteristics. As a result, anisotropic gratings using H-LCP were obtained with a high diffraction efficiency that was 80% of the theoretical maximum efficiency (33.9%) of thin diffractive gratings. Results of experimental and theoretical investigation reveal that the resultant molecular direction and optical anisotropy are generated and controlled by LPUV exposure. This agrees well with H-LCP behavior confirmed on the basis of polarization UV-visible absorption spectra. |