Enhanced stability of the second order optical properties of high-Tg fluorinated electro-optic copolymer

In this work the authors investigated the second order nonlinear optical properties of a group of Disperse Red 1 based electro-optic fluorinated copolymers, synthesized with two fluorinated monomers: the alpha-fluoroacrylate monomer bearing an adamantane side group and the alpha-fluoroacrylate monomer bearing the Disperse Red 1 chromophore. By means of nonlinear ellipsometry at lambda=1550 nm, the poling induced electro-optic tensor main component r(33) was determined. The polymer's thermostability was investigated by means of the temperature scanning and isothermal relaxation techniques, leading to the determination of the depolarization temperature T-dep=136 degrees C, corresponding to an activation energy for the relaxation of the orientational distribution of the active chromophores E-A=105 kcal/mol. The increased thermostability of the copolymer, given by the adamantane side group, is then compared with that of other two groups of fluorinated copolymers. (c) 2006 American Institute of Physics.