Comparison of nonlinear absorption in three similar dyes: Polymethine, squaraine and tetraone

Excited state absorption and decay kinetics of near IR polymethine dyes

“…The absorption bands of SD 2878 and TD 2824 (especially TD 2824 as a polyene structure) are blue shifted when compared to the corresponding PD 2658. These shifts correlate with increasing electron acceptor strength in the bridge leading to a decrease in effective conjugation length due to bond lengthening in the acceptor groups [9].…”

“…1 and 2. Their chemical names are: 5-butyl-4- We also perform a comparison of the linear and nonlinear properties of this set of near IR dyes (PD 2658, SD 2878, and TD 2824) and a set of visible dyes (PD 2630, SD 2243, and TD 2765), which were investigated by us previously, with the only difference being in the terminal groups and their effect on the effective conjugation length [8,9]. The extinction coefficients for the investigated dyes in butanol are: 0.99 Â 10 5 M À1 cm À1 at a peak position of 885 nm for PD 2371, 2.11 Â 10 5 M À1 cm À1 at a peak position of 980 nm for PD 2658, 1.37 Â 10 5 M À1 cm À1 at a peak position of 1096 nm for PD 2716, 1.18 Â 10 5 M À1 cm À1 at a peak position of 1223 nm for PD 2892, 1.71 Â 10 5 M À1 cm À1 at a peak position of 963 nm for SD 2878, and 1.76 Â 10 5 M À1 cm À1 at a peak position of 813 nm for TD 2824.…”

Synthesis, Crystal Structure, Spectral and Thermodynamic Properties of One Benzoindole Pentamethine Cyanine Dye

“…Benzoindole pentamethine cyanine dyes have been extensively applied in the fields of biomacromolecule fluorescent labeling, [1][2][3] nonlinear optical materials 4 and optical disc storage, [5][6] due to their stability and excellent spectral properties, including large molar extinction coefficients, broad wavelength tunability, and particularly their high near-infrared (NIR) absorption and emission wavelengths.…”

Limiting the intensity of femtosecond pulses with anti-stokes excitation of organic dye solutions

“…Nevertheless, there are data of quantum-chemical calculations demonstrating that at least three intensive PC 823 transitions (S 1 →S 2 , S 1 →S 3 , and S 1 → S 4 ) with oscillator forces f(1 → 2,3,4) = 0.1-0.3 (the oscillator force of the main S 0 → S 1 long-wavelength transition f(0 → 1) = 1.4) fall within the titanium-sapphire laser radiation band. It should be noted that the intensity of these transitions, according to the calculated results, is much greater than that of the experimentally observed S 0 → S n transitions near 532 nm [6,11,12] with the oscillator force that does not exceed f ≈ 0.05 and is responsible for the limiting dye characteristics with excitation by radiation of the second harmonic of the Nd-YAG laser. The calculated oscillator forces of transitions in the titanium-sapphire laser radiation band correspond to the above estimates required to reach the limiting intensity observed in the experiment.…”