title: Outstanding poling stability of a new cross-linked nonlinear optical (NLO) material from a low molecular weight chromophore.
abstract: In this paper we report the synthesis and characterization of a trihydroxylated nonlinear optical (NLO) azochromophore and its functionalization with 2,4-tolylendiisocyanate (TDI) to give an amorphous mixture of isomers that was used as a starting compound for the preparation of cross-linked electro-optic (EO) thin films. An unedited type of thermal cross-linking reaction was used, exploiting the reactivity of isocyanate groups themselves in the presence of N,N-dimethylacetamide, without the addition of any hydroxylated comonomer as usual in the preparation of polyurethanes. Thin films were prepared by spin coating and corona poled during thermal cross-linking. A d(33) value of 33 pm/V was obtained by second-harmonic generation (SHG) measurements on poled films, and an excellent stability of SHG signal was shown upon aging at 130 °C and during dynamic thermal stability measurements.
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia snc, 80126 Napoli, Italy. fabio.borbone@unina.it
authors.forename: Fabio
authors.initials: F
authors.lastname: Borbone
authors.forename: Antonio
authors.initials: A
authors.lastname: Carella
authors.forename: Antonio
authors.initials: A
authors.lastname: Roviello
authors.forename: Mauro
authors.initials: M
authors.lastname: Casalboni
authors.forename: Fabio
authors.initials: F
authors.lastname: De Matteis
authors.forename: Glauco
authors.initials: G
authors.lastname: Stracci
authors.forename: Fabio
authors.initials: F
authors.lastname: della Rovere
authors.forename: Andrea
authors.initials: A
authors.lastname: Evangelisti
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Dispenza