The variables in the Equation 13 are defined as follows: α represents the fine structure constant, 𝑎 represents the Bohr radius; c represents the speed of light in a vacuum. The 2PA cross sections obtained for these molecules are large which suggests that the investigated chromophores are promising as new organic materials for NLO. The 2PA cross section obtained for PPAB-2 (δ TP = 6354 a.u. at 1771 nm) is five times higher than PPAB-3 (δ TP = 1136 a.u. at 1560 nm, see Table ). The two molecules consist of very similar molecular structure but two different lateral donor groups: TPA vs. DPA. Our results indicate that due to the π linker in PPAB-2 is Thienyl whereas in PPAB-3 it is phenylene linker leading to enhanced ICT and consequently larger two-photon absorption in PPAB-2. The 2PA cross-section can also be significantly enhanced through careful modification of the donor and the linker substituents. These results indicate that the present study could serve as basis for studies of second and third-order NLO properties of ICT-based chromophores consisting of PPAB electronic acceptor with suitable electronic donor and π-linkers with Dπ-A framework for future technological applications.