Enhanced photorefractive two-beam coupling in low- T g polymeric materials with a new device structure
Enhanced photorefractive two-beam coupling in low- T g polymeric materials with a new device structure
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采用新器件结构增强低 Tg 聚合物材料中的光折变双光束耦合
DOI：
10.1364/josab.21.001255
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发表时间：
2004
影响因子：
1.9
通讯作者：
T. Wada
中科院分区：
文献类型：
--
作者：
T. Sassa;T. Muto;T. Wada
通过在具有低玻璃化转变温度（Tg）的光折变聚合物中使用一种新型器件结构，观察到了在低驱动电压和小光栅间距下的大的双光束耦合增益。当外电场为1.40 V/μm，光栅间距为0.42 μm时，净增益（Γ−α）L接近1。与传统器件结构相比，优化了参数，提高了有效电光系数、相移、空间电荷场和有效相互作用长度，增强了耦合强度。此外，这种耦合强度增强的机制被发现适用于典型的高效低Tg聚合物材料。
Large two-beam coupling gain with a low driving voltage and a small grating spacing was observed by use of a novel device structure in a photorefractive polymer with a low glass-transition temperature (Tg). A net gain (Γ−α)L close to 1 was observed for an external electric field of ∼40 V/μm and a grating spacing of 0.42 μm. The enhanced coupling strength was the result of optimized parameters and improved, effective electro-optical coefficient, phase shift, space-charge field, and effective interaction length compared with those of a conventional device structure. Moreover, mechanism for this enhancement of coupling strength was found to be applicable to typical efficient low-Tg polymeric materials.