Two photon spectra of organic salt trans 4 [p (N hydroxyethyl N methylamino)sty

Two-photon absorption (TPA) cross sections of an organic dye, trans-4-[p-(N-hydroxyethyl-N-methylamino)styryl]-N-methylpyridinium iodide (abbreviated as ASPI), from 810 to 1100 nm have been measured in two solvents (benzyl alcohol, dimethyl formamide (DMF)) with different polarities. The peak values