Three two-photon absorption （TPA） tribranched chromophores were successfully prepared, in which 1,3,5-triazine is been as electron deficient core, 1,4-phenylenedivinylene as conjugated bridge, 3,4-ethylenedioxy- thiophene （EDOT） （T1）, N-methylpyrrole （T2） or triphenylamine （T3） as electron-donating end-groups. Their pho- tophysical properties were studied by absorption, one- and two-photon fluorescence and TPA cross-section deter- mination. The nonlinear transmission （NLT） measurement in femtoseconds （fs） regime at 800 nm indicates that TPA cross-section σ2 values of T1, T2 and T3 with extended π-conjugated bridge are much larger than the corresponding chromophore T4 with a short length bridge, and TPA cross-section of T1 with end-groups EDOT exhibits a remarkable enhancement compared with T2 and T3 having the same length It-system. The chromophores T1, T2 and T3 show also remarkable up-converted luminescence and optical limiting activity.
A series of new fluoro-containing copolymers have been synthesized by a Mitsunobu reaction with 4,4＇-（hexafluoroisopropylidene） bisphenol A（6FBPA） and the corresponding N,N-dihydroxyethylaminoaryl azo or ring-locked triene compounds, which have high thermal stability and good solubility in organic solvents.The nonlinear optical（NLO） measurements made by Marker fringe method at 1064 nm indicate that the copolymers embedded with the ring-locked triene and azo chromophores exhibit higher macroscopic nonlinear optical coefficient（70.2 pm/V and 26.5-34.6 pm/V,respectively）.Thermal analysis and UV-visible absorption spectra show that the copolymers have good thermal stability（T_d= 264-319℃） and optical transparency （λ_（max）500 nm）.
Jie Ping Shi Hui Yang Li Wei Hong Wen Hu Guo Yuan Lu
