標題: | Synthesis and relationships between the nonlinear optical and holographic properties of dual functional azocarbazole chromophores based on photorefractive polymers |
作者: | Chang, CJ Whang, WT Hsu, CC Ding, ZY Hsu, KY Lin, SH 材料科學與工程學系 光電工程學系 Department of Materials Science and Engineering Department of Photonics |
公開日期: | 24-Aug-1999 |
摘要: | Two kinds of dual functional carbazole-based chromophores are synthesized to enhance the photorefractive (PR) performance of the polymers by attaching the electron-donating and electron-accepting groups with a diazo bridge on the 3- and 6-positions of the N-ethylcarbazole. The electron-donating group is N,N-diethanol aminophenyl. The electron-accepting group is either p-nitrophenyl or 5-nitrothiazole. The peak maximum of the UV/vis absorption spectra of the 5-nitrothiazole-containing chromophore PANTAC at 535 nm is longer than that of the p-nitrophenyl-containing PANPAC at 477 nm. Both chromophores exhibit a large first hyperpolarizability in the hyper-Rayleigh scattering experiment due to the extended chain length. The first hyperpolarizability of PANTAC is 1100 x 10(-30) esu, almost the double of that of PANPAC (590 x 10(-30) esu). The diffraction efficiencies of both polymers are the function of the film thickness and the laser beam wavelength with a maximum eta(max) at a thickness d(max) between 15 and 23 mu m Surprisingly, the PANPAC-based PR polymer reveals a higher maximum diffraction efficiency (eta(max)) and better fringe of the stored holograms than the PANTAC-based PR polymer does. Both the PR polymers written/read by the green/red laser have greater eta(max) values than those written/read by the green/green laser. These phenomena are related to the balance between absorption and transmission of the laser beam through the PR polymer. |
URI: | http://dx.doi.org/10.1021/ma981922d http://hdl.handle.net/11536/31146 |
ISSN: | 0024-9297 |
DOI: | 10.1021/ma981922d |
期刊: | MACROMOLECULES |
Volume: | 32 |
Issue: | 17 |
起始頁: | 5637 |
結束頁: | 5646 |
Appears in Collections: | Articles |
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