Large third-Order nonlinearity of new π-conjugated donor-acceptor polymers with substituted Thiophene and 1,3,4-Oxadiazole moieties

Restricted Access.We present the synthesis of two newly designed, thiophene-based conjugated polymers (P1 and P2) carrying 1,3,4-oxadiazole, 3,4-dinaphthyloxy thiophene, and 3,4-dialkoxy thiophene moieties as potential NLO active materials. Their NLO properties have been investigated both by the Z-scan and degenerate four-wave mixing (DFWM) techniques using 532 nm, 7 nanosecond laser pulses. The measured β and χ(3) values for the polymers are found to be in the range of 10−11 m/W and 10−11 esu, respectively. The results indicate that they exhibit good optical-limiting behavior and are promising materials for nonlinear optical applications due to effective two-photon absorption (TPA)