Study on the three-photon properties of a triphenylamine derivative with three conjugated branches

Three-photon pumped frequency-upconversion fluorescence and nonlinear transmission properties of tris-[4-(2-{4-[5-(4-tert-butyl-phenyl)-[1,3,4]oxadiazol-2-yl]-phenyl}-vinyl)-phenyl]-amine (TPAD3) are studied using a Ti:Sapphire oscillator-amplifier system associated with an optical-parametric amplifier, which could specifically provide ∼80 fs duration and 1175-1300 nm laser pulses for three-photon excitation. The dye shows very efficient three-photon pumped frequency-upconversion fluorescence and three-photon absorption at wavelengths from 1175 nm to 1300 nm. In our study, the beam intensity distribution is also taken into account. For the first time we give the analytical solution to nonlinear transmission of a three-photon absorption process when the incident beam has a Gaussian transverse spatial profile.