Absolute Measurement of Two-Photon Cross Sections

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]. The wavelength of peak fluorescence emission versus pump pulse intensity is depicted in Figs 14a, 16a, 20a and 22a.…”

“…. The two-photon absorption cross-sections of dye molecules were measured previously by fluorescence analysis [9][10][11][12][13][14][15]. In a recent paper [16] the S 0 -S" (n ^ 2) two-photon absorption dynamics of rhodamine dyes was studied by transmission measurements and theoretical simulations.…”

Problems in laser spectroscopy

“…Например, сложным является измерение абсолютной величины сечения двухквантового поглощения, так как такие измерения чувствительны к пространственно-временной неоднородности излучения лазера. Отме-тим, что удобный метод таких измерений предложен недавно в работе 149 . Малость коэффициента двухфотонного поглощения затрудняет примене-ние метода к частицам, имеющим низкую концентрацию (< Ю ао см~3).…”

Applications of ultrafast lasers to two-photon fluorescence and lifetime imaging

“…For subsequent use of a fluorescent probe in a biological sample, where different experimental constraints apply, femtosecond pulsed operation is used. The theoretical description of the multi-photon excitation process has been described extensively in the literature [6][7][8][9][10][11][12][13][14] . In summary for the case of twophoton absorption, the number of absorbed photons N abs in a sample of concentration C (assumed constant) and sample volume V, when excited by a pulse I(r, t) is given by 13 :…”