Relationship between Dipole Moment of Chromophores and Photoinduced Birefringence
Relationship between Dipole Moment of Chromophores and Photoinduced Birefringence
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发色团偶极矩与光致双折射的关系
DOI：
10.1143/jjap.45.456
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发表时间：
2006
影响因子：
1.5
通讯作者：
T. Fukuda
中科院分区：
文献类型：
--
作者：
Jun Young Kim;T. Fukuda
本文报道了由非极性长π共轭发色团和极性发色团组成的无定形偶氮苯共聚物的光致双折射（Δn）性质的研究结果。特别地，我们研究了发色团的偶极矩平衡与可用于全息数据存储的Δn特性之间的关系。通过旋涂（d=0.8 μm）获得聚合物膜，并用线性偏振Ar+离子激光束（λ=488 nm，辐照度= 1 W/cm 2）照射。然后用He-Ne（λ=633 nm）激光同时用偏振计探测Δn，并根据膜厚进行校准。根据结果，观察到的Δn值随着两个发色团之间的偶极矩差的增加而减小。就本实验的研究而言，聚{4-[2-（甲基丙烯酰氧基）乙氧基]-2-甲基-4-（苯基偶氮）偶氮苯-co-4-[2-（甲基丙烯酰氧基）乙氧基]-4 '-氰基偶氮苯}获得了最大的光致双折射值，为0.244。这可能是从偶极匹配的观点来解释的，偶极匹配将有助于共聚物中两个偶氮发色团之间的分子合作运动。
In this paper, we describe the result of studies on photoinduced birefringence (Δn) properties of amorphous azobenzene copolymer consisting of nonpolar long π-conjugated chromophore and polar chromophores. In particular, we studied the relationship between the dipole moment balance of chromophores and the Δn properties that can be used for holographic data storage. The polymer films were obtained by spin coating (d=0.8 µm) and were irradiated with a linear polarized Ar+ ion laser beam (λ=488 nm, irradiance = 1 W/cm2). Then the Δn was probed simultaneously with a He–Ne (λ=633 nm) laser using a polarimeter and calibrated in relation to film thickness. From the result, the observed Δn value decreased as the difference in the dipole moment between the two chromophores increased. As far as the investigation in this experiment are concerned, the largest photoinduced birefringence value, 0.244, was achieved with the poly{4-[2-(methacryloyloxy)ethyloxy]-2-methyl-4-(phenylazo)azobenzene-co-4-[2-(methacryloyloxy)ethyloxy]-4'-cyanoazobenzene}. This might be explained from the viewpoint of the dipole matching that will contribute molecular cooperative motion between two azo chromophores in the copolymer.