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 sidechain 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.
L. Angiolini, L. Giorgini, A. Golemme, Q. Lhi, F. Mauriello, R. Termine (2009). High Tg azopolymers for Photorefractive applications. CHEMISTRY OF MATERIALS, 21, 2403-2409 [10.1021/cm8034664].
High Tg azopolymers for Photorefractive applications
ANGIOLINI, LUIGI;GIORGINI, LORIS;
2009
Abstract
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 sidechain 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
