High Tg, Nonpoled Photorefractive Polymers

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• 作者：Huawei Li ; Roberto Termine ; Luigi Angiolini ; Loris Giorgini ; Francesco Mauriello ; Attilio Golemme
• 刊名：Chemistry of Materials
• 出版年：2009
• 出版时间：June 23, 2009
• 年：2009
• 卷：21
• 期：12
• 页码：2403-2409
• 全文大小：174K
• 年卷期：v.21,no.12(June 23, 2009)
• ISSN：1520-5002

文摘

Room-temperature photorefractivity without prepoling was demonstrated in polymers and copolymers with a glass transition temperature well above 100 °C. The compounds used are multifunctional side-chain polymers exhibiting chiral, semiconducting, photochromic, and nonlinear optical (azoaromatic moieties) properties. The photorefractive performance was linked to the reorientational effect of the photogenerated space-charge field, which well below the glass transition temperature can be active in the presence of the conformational mobility achieved via the trans−cis light-induced isomerization. The grating build-up time, which is long at λ = 633 nm (with a time constant τ ≈ 500−1000 s) decreases by 2 orders of magnitude at λ = 532 nm, where absorption is higher.