Two-photon absorption cross section for Coumarins 102, 153 and 307

Abstract

Abstract. Two-photon absorption cross sections of Coumarins 102, 153, 307 solutions in methanol in the wavelength range of 730-870 nm were measured. The maximum cross section for two-photon absorption in this wavelength range were 267, 369, 287 GM for Coumarins 102, 153, 307, respectively. The absolute value of the cross sections was determined by comparison with a fluorescein (43 GM at a wavelength of 790 nm). The dependence of the two-photon absorption cross section on the excitation wavelength coincides with the shape of the single-photon absorption cross section. IntroductionMany novel research methods based on two-photon absorption (TPA), in particular multiphoton fluorescence microscopy, photodynamic therapy with TPA are currently being intensively developed. These methods use fluorescent probes, which are usually organic phosphors. Coumarins as a class of compounds are among the most versatile and widely used fluorescent probes. In biological preparations, coumarins show a high degree of sensitivity to the environment [1]. The photophysical properties of coumarins are well understood, however data on the TPA of coumarins are poor. The aim of this work was to study TPA of Coumarins 102, 153 and 307 in methanol solutions.It was found in paper [2] that the shape of the TPA cross section coincides with the one-photon absorption for the Coumarin 102 solution in methanol. This effect is possible in the absence of a central symmetry in the molecule and was observed earlier for certain organic phosphors [3]. The use of this type of phosphors as standards makes it possible to simplify the relative measurements of the TPA cross section. The Coumarins 102, 153 and 307 with a single-photon absorption maximum in the 375-435 nm region were chosen as the object of measurements, since their two-photon absorption corresponds to the widely used 730-870 nm range.

Effect of spatial folding of molecules on two-photon absorption and nonlinear refraction in foldamers

“…The excellent quantitative match of the TPA data for C153 (Fig. 3c) with that in the literature 43 validated the standardization of our measurements and calculations.…”

Synthesis and Photodynamics of Stilbenyl‐Azopyrroles: Two‐Photon Controllable Photoswitching Systems

“…were subscript 1 and 2 correspond to the standard (coumarin 153, C153) and problem systems (stilbenyl‐azopyrroles), respectively, δ are the biphotonic absorption coefficients at 800 nm, ( δ C153 =29 GM), F are the integrated two‐photon fluorescence, Φ are de fluorescence quantum yields and C are the molar concentrations. To best of our knowledge, it is the first time that this approach was used to determine the biphotonic absorption coefficients.…”

Investigations of Thienoacene Molecules for Classical and Entangled Two-Photon Absorption

“…Emission spectra were measured using a Varian Cary Eclipse spectrophotometer. Fluorescence quantum yield of the compounds were measured using Coumarin 307 (Φ = 0.81) and Rhodamine B (Φ = 0.70) as standards. Slopes of fluorescence intensity as a function of concentration of the standard and sample were used to calculate the quantum yield using a known method …”