NOVEL OPTICALLY TRANSPARENT POLYESTERS CONTAINING A HIGH-DENSITY OF 2ND-ORDER NONLINEAR OPTICALLY-ACTIVE CHROMOPHORES

The syntheses and second-order non-linear optical (NLO) properties of novel types of optically transparent polyesters containing a high dens ity of second-order NLO-active chromophores are described. The chromop hores used in this study contained either a perfluorooctyl- or an octy l-sulfonyl moiety-as the electron-withdrawing group at the pi-conjugat ing sites. The polyesters are prepared by condensation polymerization between isophthalic acid derivatives and xyethyl)-4-(perfluorooctylsul fonyl)anilino]ethanol by the use of triphenylphosphine and diethyl azo dicarboxylate as the condensation reagents, The amorphous polyesters o btained, the optical transparency of which was down to 390 nm, exhibit ed good solubility in common organic solvents and provided optical-qua lity films by spin-coating. In addition, second-harmonic generation (S HG) measurements of spin-coated films of the polyesters were carried o ut by the Maker fringe method; using a Q-switched Nd:YAG laser as the exciting beam after poling treatment. One of the polyesters, which was prepared from (perfluorooctylsulfonyl)anilino]ethoxy}isophthalic acid and yethyl)-4-(perfluorooctylsulfonyl)anilino]ethanol, exhibited the desired optical-transparency and a second-order NLO coefficient, d(33) , of 3.0 pm V-1.