Excited-state characterization and effective three-photon absorption model of two-photon-induced excited-state absorption in organic push-pull charge-transfer chromophores

AbstractDuring the absorption of a laser pulse of moderate length, the leading edge can experience excited state absorption out of the first singlet state. The measurement of this excited state absorption spectrum can only be accurately probed using short pulse pump-probe techniques. Specifically, we examine the excited state absorption of AF-380 in THF using ultrafast transient white light absorption spectroscopy (TWLA). This material has been the focus of several investigations due to it's purported large two-photon absorption cross-section, the discrepancies between long and short pulse measurements, and it's use in holographic twophoton induced photopolymerization. It is believed that a substantial excited state absorbance can account for the difference in two-photon cross section measurements. It is also possible that this excited state exhibits coherence for time scales that can affect further absorption of longer pump pulses. We examine the transient absorption of this species, as well as polarization and free carrier effects and discuss the possible implications with regards to measurement techniques.

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STUDY OF THE S1 AND S2 EXCITED STATES OF GAS-PHASE PROTONATED SCHIFF BASE RETINAL CHROMOPHORES IN ONE AND TWO PHOTON ABSORPTION

Journal of Theoretical and Computational Chemistry ◽

10.1142/s0219633611006372 ◽

2011 ◽

Vol 10 (02) ◽

pp. 121-132 ◽

Cited By ~ 2

Author(s):

YUANZUO LI ◽

PENG SONG ◽

YING SHI ◽

YONG DING ◽

FENGJIE ZHOU ◽

...

Keyword(s):

Schiff Base ◽

Excited State ◽

Charge Transfer ◽

Gas Phase ◽

Excited States ◽

Density Functional ◽

Three Dimensional ◽

Photon Absorption ◽

Two Photon ◽

The One

The S1 and S2 excited states of gas-phase protonated Schiff base retinal chromophores in the one- and two-photon absorptions (TPAs) are investigated with time-dependent density functional theory. In one-photon absorption, the two-dimensional (2D) site and three-dimensional (3D) cube representations reveal that S1 and S2 excited states of gas-phase protonated Schiff base retinal chromophores are all charge transfer excited states. To better study the weak S2 excited states of gas-phase protonated Schiff base retinal chromophores, we investigated theoretically excited state properties of them in TPA. For 11-cis dimethyl retinal, it is found that the cross section of S2 excited state is 51.04 GM in PTA, which is only slightly smaller than that of S1 (77.04 GM) in TPA. Therefore, the S2 excited state of 11-cis dimethyl retinal can be clearly observed in TPA experiment. The 2D site and 3D cube representations reveal that electronic transition from S1 to S2 excited state of gas-phase protonated Schiff base retinal chromophores in TPA are also of charge transfer character.

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Broadband Excited State Dynamics of Common Reverse Saturable Absorbing Dye Media.

MRS Proceedings ◽

10.1557/proc-374-375 ◽

1994 ◽

Vol 374 ◽

Cited By ~ 1

Author(s):

Kenneth J. McEwan ◽

Richard C. Hollins

Keyword(s):

Excited State ◽

Organic Liquid ◽

Excited State Absorption ◽

Photon Absorption ◽

Excited State Lifetime ◽

Absorption And Emission ◽

Two Photon Absorption ◽

Two Photon ◽

State Response ◽

Photon Excitation

AbstractIn this paper we describe a technique by which the broadband excited state absorption/emission and dynamics can be measured for materials with either linear or two photon absorption. The technique is applied to two different dyes in solution and to a cyano-biphenyl organic liquid. The ratio of σex/σgr for HITCI in methanol is greater than 1 from 400 to 570nm and at 532nn is determined to be 25; the excited state lifetime is 800ps. For CAP in methanol σex/σgr is greater than 1 from 400–650nm and is 14 at 532nm. Dimer absorption and emission are found to contribute to the excited state response in this material. In the organic liquid broadband (400–570nm) excited state absorption is measured following two photon excitation at 588nm.

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PICOSECOND-INDUCED NONLINEAR ABSORPTION IN LIQUID CRYSTAL MEDIA

Journal of Nonlinear Optical Physics & Materials ◽

10.1142/s0218863595000100 ◽

1995 ◽

Vol 04 (01) ◽

pp. 245-260 ◽

Cited By ~ 8

Author(s):

K. J. McEWAN ◽

R. C. HOLLINS

Keyword(s):

Experimental Data ◽

Liquid Crystal ◽

Excited State ◽

Nonlinear Absorption ◽

Excited State Absorption ◽

Photon Absorption ◽

Isotropic Phase ◽

Pump Probe ◽

Two Photon Absorption ◽

Two Photon

The contributions to the nonlinear absorption of liquid crystal media in their isotropic phase are measured using a picosecond pump/probe technique at 587 nm. Good agreement between the experimental data and theory is obtained by assuming that two-photon absorption and excited state absorption dominate the nonlinear optical response. The important parameters are extracted from the experimental data and it is shown that the nonlinear absorption depends strongly on the molecular structure. The lifetime of the excited state is measured and found to compare well with the fluorescence lifetime.

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Two-photon absorption and two-photon assisted excited-state absorption in CdSe0.3S0.7quantum dots

Journal of Optics A Pure and Applied Optics ◽

10.1088/1464-4258/11/6/065206 ◽

2009 ◽

Vol 11 (6) ◽

pp. 065206 ◽

Cited By ~ 9

Author(s):

Feng Wu ◽

Guilan Zhang ◽

Wei Tian ◽

Wenju Chen ◽

Guofeng Zhao ◽

...

Keyword(s):

Excited State ◽

Excited State Absorption ◽

Photon Absorption ◽

Two Photon Absorption ◽

Two Photon

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Red to Green Upconversion in Er3+-Doped BaTiO3 Nanorods

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.18426 ◽

2008 ◽

Vol 8 (12) ◽

pp. 6564-6568 ◽

Cited By ~ 4

Author(s):

Márcio A. R. C. Alencar ◽

Glauco S. Maciel ◽

Cid B. de Araújo ◽

Amitava Patra

Keyword(s):

Excited State ◽

Excitation Spectrum ◽

Ground State ◽

Laser Power ◽

Excited State Absorption ◽

Photon Absorption ◽

Absorption Process ◽

Two Photon Absorption ◽

Two Photon ◽

Upconversion Emissions

We investigated the frequency upconversion (UC) process in BaTiO3:Er3+ nanocrystals for excitation wavelengths in the range 638 to 660 nm. Green upconversion emissions at 526 and 547 nm corresponding to 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 to transitions of the Er3+ were observed. The excitation spectrum for UC emissions presented three bands, due to ground state and excited state absorption of Er3+ ions. The UC intensity as a function of the laser power was investigated and it was found this a two-photon absorption process.

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