Measurement of strong nonlinear absorption in stilbene-chloroform solutions, explained by the superposition of two-photon absorption and one-photon absorption from the excited state

1974 ◽  
Vol 24 (1) ◽  
pp. 133-135 ◽  
Author(s):  
J. Kleinschmidt ◽  
S. Rentsch ◽  
W. Tottleben ◽  
B. Wilhelmi
Keyword(s):  
Excited State ◽  
Nonlinear Absorption ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon

PICOSECOND-INDUCED NONLINEAR ABSORPTION IN LIQUID CRYSTAL MEDIA

1995 ◽  
Vol 04 (01) ◽  
pp. 245-260 ◽  
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.

New two-photon absorption benzotriazole–coumarin dyads: the evidence of internal proton transfer in the excited state

2015 ◽  
Vol 56 (1) ◽  
pp. 236-242 ◽  
Author(s):  
Yulong Gong ◽  
Yao Lu ◽  
Zhenqiang Wang ◽  
Shengtao Zhang ◽  
Ziping Luo ◽  
...  
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon

scholarly journals Ultrafast processes triggered by one- and two-photon excitation of a photochromic and luminescent hydrazone

2019 ◽  
Vol 15 ◽  
pp. 2438-2446 ◽  
Author(s):  
Alessandro Iagatti ◽  
Baihao Shao ◽  
Alberto Credi ◽  
Barbara Ventura ◽  
Ivan Aprahamian ◽  
...  
Keyword(s):  
Excited State ◽  
Cross Section ◽  
Absorption Cross Section ◽  
Transient Absorption ◽  
Solvent Polarity ◽  
Photon Absorption ◽  
Absorption Cross ◽  
Time Resolved ◽  
Two Photon Absorption ◽  
Two Photon

In this work we apply a combination of steady state and time resolved luminescence and absorption spectroscopies to investigate the excited-state dynamics of a recently developed molecular photoswitch, belonging to the hydrazone family. The outstanding properties of this molecule, involving fluorescence toggling, bistability, high isomerization quantum yield and non-negligible two-photon absorption cross section, make it very promising for numerous applications. Here we show that the light induced Z/E isomerization occurs on a fast <1 ps timescale in both toluene and acetonitrile, while the excited state lifetime of the Z-form depends on solvent polarity, suggesting a partial charge transfer nature of its low lying excited state. Time-resolved luminescence measurements evidence the presence of a main emission component in the 500–520 nm spectral range, attributed to the Z-isomer, and a very short living blue-shifted emission, attributed to the E-isomer. Finally, transient absorption measurements performed upon far-red excitation are employed as an alternative method to determine the two-photon absorption cross-section of the molecule.

scholarly journals Impact of the Subunit Arrangement on the Nonlinear Absorption Properties of Organometallic Complexes with Ruthenium(II) σ-Acetylide and Benzothiadiazole as Building Units §

Inorganics ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 67
Author(s):  
Eleonora Garoni ◽  
Alessia Colombo ◽  
Kenji Kamada ◽  
Claudia Dragonetti ◽  
Dominique Roberto
Keyword(s):  
Electron Acceptor ◽  
Cross Sections ◽  
Nonlinear Absorption ◽  
Organometallic Complexes ◽  
Photon Absorption ◽  
Absorption Cross ◽  
Absorption Properties ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Resonance Enhancement

In this paper, the nonlinear absorption properties of two complexes consisting of Ru(C≡CPh)(C≡C)(dppe)2 (dppe = Ph2PCH2CH2PPh2) as electron donor (D) and 4,7-di(2-thienyl)benzo[c][1,2,5]thiadiazole as electron acceptor (A) units in two different arrangement, i.e., A–D–A and D–A–D, are presented. They were measured in solution by the femtosecond open-aperture Z-scan method. The complexes show moderate two-photon absorption cross-sections σ(2) of several hundred to one thousand GM (here 1 GM = 10−50 cm4 s molecule−1 photon−1). Although they are formed by the same building units, it was found that the two-photon absorption values of the D–A–D arrangement are six times higher than that of the A–D–A one. This difference can be explained by the number of metal cores (one or two ruthenium centers), the geometrical configurations of the complexes (more or less planar), and the resonance enhancement by lowering the intermediate state.

NONLINEAR ABSORPTION AND OPTICAL LIMITING IN SOLUTIONS OF SOME RARE EARTH SUBSTITUTED PHTHALOCYANINES

2001 ◽  
Vol 10 (01) ◽  
pp. 113-121 ◽  
Author(s):  
K. P. UNNIKRISHNAN ◽  
JAYAN THOMAS ◽  
BINOY PAUL ◽  
ACHAMMA KURIAN ◽  
PRAMOD GOPINATH ◽  
...  
Keyword(s):  
Rare Earth ◽  
Absorption Coefficient ◽  
Nonlinear Absorption ◽  
Optical Limiting ◽  
Photon Absorption ◽  
Open Aperture ◽  
Pulse Excitation ◽  
Two Photon Absorption ◽  
Two Photon ◽  
532 Nm

Effective nonlinear absorption coefficient, β eff , of solutions of some rare earth substituted phthalocyanines (viz: Sm(Pc)2, Eu(Pc)2 and LaPc) was measured using open aperture Z-scan technique under nanosecond pulse excitation at 532 nm. The effect of nonlinear absorption on optical limiting in these samples was also investigated. Both nonlinear absorption and optical limiting phenomena in these samples are attributed to sequential two-photon absorption (STPA) process.

Two-Photon Absorption and Excited State Dynamics of Two Organic Molecules Containing Donor/Acceptor Moieties

2008 ◽  
Vol 25 (7) ◽  
pp. 2456-2459 ◽  
Author(s):  
Yan Yong-Li ◽  
Li Bo ◽  
Liu Kang-Jun ◽  
Dong Zhi-Wei ◽  
Ma Guo-Hong ◽  
...  
Keyword(s):  
Excited State ◽  
Organic Molecules ◽  
Photon Absorption ◽  
Excited State Dynamics ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Donor Acceptor
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