Laser emission from two xanthene dyes via double-photon excitation

S0-S1 two photon absorption dynamics of organic dye solutions

“…The best-fitting <7 (2) and G\ X values are included in Table I. For rhodamine 6G two-photon absorption cross-sections have been reported already (same excitation wavelength) [9][10][11][37][38][39] Table I and cross-section spectra are given in [30].…”

“…For a typical SQ-SJ two-photon absorption cross-section of cr (2) = 2 x 10~4 9 cm 4 s (see results below) and t eS = At L = 5ps, the two-photon saturation intensity is 7 S (2) « 4 x 10 n Wcm 2 (A L = 1.054 /mi). In the experiments the non-linear transmission measurements are carried out for I OL <^ 7 S (2) so that ground-state depletion does not influence the two-photon absorption process.…”

“…The two-photon absorption in dye solutions is applied for the duration measurement of picosecond laser pulses by fluorescence trace analysis [1]. Dye laser action was achieved by two-photon excitation [2,3]. The two-photon absorption may act as a power limiter in high-power lasers [4][5][6].…”

S0-Sn Two-Photon Absorption Dynamics of Rhodamine Dyes

“…The two-photon absorption of dye solutions at elevated laser intensities has been studied previously by fluorescence observation [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Two-photon absorption cross-sections G {2) were determined for various dyes [1][2][3][4][5][6][7].…”

“…The fluorescence induced by two-photon absorption has found wide application in picosecond-pulse duration measurements [8]. Dye-laser pumping by two-photon absorption was achieved [9,10]. Deviations of the two-photon excited-fluorescence signal from the expected quadratic dependence on pump-laser intensity has been observed indicating the simultaneous action of additional spectroscopic effects (excited-state absorption, stimulated emission, etc.)…”