Enhancement of lasing efficiency of sodium 8-hydroxypyrene-1,3,6-trisulfonate in aqueous solution

Excited state proton transfer dye lasers

“…Thus flash lamp excitation of an aqueous solution of sodium 8-hydroxypyrene-1,3,6-trisulfonate (SHPTS) induced losses in the photochemical laser that are related to the absorption of the laser radiation from the deprotonated form of SHPTS by the hydrated electron produced from this excited form. 132 The light absorption by the hydrated electron leads to a decrease in the efficiency and narrows the lasing spectrum of SHPTS. In the laser excitation, the induced loses in this laser are small.…”

“…101 A decrease in the hydrated electron concentration due to its interaction with electron acceptors results in a decrease in these induced losses and an increase in the laser radiation efficiency of SHPTS in the lamp excitation. 132 If the 7-aminonaphthalene-1,3-disulfonate dianion is formed in acidic solutions by the reaction of an acid photodissociated monoanion with the protonated amino group, the efficiency of the lasing upon pulse photoexcitation is considerably higher compared to that upon direct excitation from the ground state in neutral solutions. 22 This increase in efficiency is rationalised as a decrease in losses, due to the induced T n /T 1 absorption of light by the 7-aminonaphthalene-1,3-disulfonate dianion upon protonation of the amino group of the dianion triplet (s 67 < s 6 H 7 H ) in acidic solutions and a decrease in losses, caused by the light absorption by the hydrated electron, as a result of the effective reaction of the electron with the proton.…”