A new dye trans-4-[p-(N-hydroxyethyl-N-methylamino)styryl]-N-methylpyridini
um p-toluene sulphonate (abbreviated as HMASPS) was synthesized, the two-ph
oton absorption (TPA), TPA-induced frequency upconversion emission, and two
-photon pumped (TPP) frequency up-converted lasing properties of HMASPS wer
e experimentally studied. This new dye has a moderate TPA cross-section of
sigma (2) = 6.0 x 10(-48) cm(4) s photon(-1), but exhibits a high lasing ef
ficiency. The net conversion efficiency from the absorbed 1064 nm pump puls
e energy to the 630 nm up-converted lasing energy is 4% at a pump energy le
vel of 4 mJ.