Strong Enhancement of the Two Photon Absorption Cross Section of Porphyrin J-Aggregates in water

2004 ◽  
Vol 846 ◽  
Author(s):  
Elisabetta Collini ◽  
Camilla Ferrante ◽  
Renato Bozio
Keyword(s):  
Cross Section ◽  
Absorption Cross Section ◽  
Laser Pulses ◽  
Photon Absorption ◽  
Absorption Cross ◽  
Cooperative Effects ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Strong Enhancement ◽  
The One

ABSTRACTStrong enhancement of the two photon absorption (TPA) cross section at 812 nm is observed for tetrakis(4-sulphonatophenyl)porphyrin diacid (H4TPPS2-) when a J-type aggregate is formed in water, in comparison to the one observed for the H4TPPS2- monomer in mixture of water, DMSO and urea. Open aperture Z-scan experiments, performed with ultra-short laser pulses, are employed to measure the TPA absorption cross section. The observed enhancement is discussed in terms of possible electronic cooperative effects in the aggregate.

Z-Scan Measurements on Molten Diphenylbutadiene in the Isotropic Liquid State

1994 ◽  
Vol 374 ◽  
Author(s):  
P. A. Fleitz ◽  
R. L. Sutherland ◽  
T. J. Bunning
Keyword(s):  
Cross Section ◽  
Absorption Cross Section ◽  
Liquid State ◽  
Laser Pulses ◽  
Photon Absorption ◽  
Wave Mixing ◽  
Absorption Cross ◽  
Isotropic Liquid ◽  
Two Photon Absorption ◽  
Two Photon

AbstractThe two-photon absorption cross-section for diphenylbutadiene heated to the isotropic liquid state has been measured using the Z-scan technique. In this experiment, the solid diphenylbutadiene was heated using a temperature controlled hot stage above its melting point. Z-scan measurements using 35ps laser pulses at 532nm were then carried out on molten diphenylbutadiene. The value of the two-photon absorption cross-section at 532nm was measured to be σ2 = (38±8) × 10−50cm4s/photon-molecule. This value corresponds well with the cross-section measured previously for diphenylbutadiene dissolved in chloroform using the degenerate four-wave mixing technique.

Syntheses and properties of acetylene-linked bis- and trisporphyrins toward two-photon photodynamic therapy

2007 ◽  
Vol 11 (06) ◽  
pp. 406-417 ◽  
Author(s):  
Yusuke Inaba ◽  
Kazuya Ogawa ◽  
Yoshiaki Kobuke
Keyword(s):  
Photodynamic Therapy ◽  
Cross Section ◽  
Sodium Salt ◽  
Absorption Cross Section ◽  
Water Soluble ◽  
Photon Absorption ◽  
Absorption Cross ◽  
Two Photon Absorption ◽  
Photon Irradiation ◽  
Two Photon

Acetylene-bridged bisporphyrins and trisporphyrins having branched bulky bis(carboxylethyl)methyl meso-substituents were synthesized. These compounds showed large effective two-photon absorption cross-section values at 890 nm measured by using a nanosecond Z-scan method. Sodium salt of hydrolyzed trisporphyrins showed broad and red-shifted Q-bands over 900 nm. Two-photon absorption cross-section values of water-soluble dimers in water were similar to, or slightly larger than, those of ester forms evaluated in toluene. Furthermore, the generation of singlet oxygen upon one-photon irradiation for dimers in water was confirmed.

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.

Diazobenzene chromophore-doped silica films with large two-photon absorption cross-section

2009 ◽  
Vol 82 (2) ◽  
pp. 204-208 ◽  
Author(s):  
Jiangtian Li ◽  
Jianlin Shi ◽  
Zhiwei Dong ◽  
Shixiong Qian ◽  
Chenyang Wei
Keyword(s):  
Cross Section ◽  
Absorption Cross Section ◽  
Photon Absorption ◽  
Absorption Cross ◽  
Silica Films ◽  
Two Photon Absorption ◽  
Two Photon

Syntheses and nonlinear absorption properties of conjugated porphyrin supramolecules

2007 ◽  
Vol 11 (05) ◽  
pp. 359-367 ◽  
Author(s):  
Kazuya Ogawa ◽  
Chihiro Hara ◽  
Yoshiaki Kobuke
Keyword(s):  
Cross Section ◽  
Communication System ◽  
Absorption Cross Section ◽  
Enhancement Factor ◽  
Electronic Communication ◽  
Photon Absorption ◽  
Absorption Cross ◽  
Absorption Properties ◽  
Two Photon Absorption ◽  
Two Photon

Self-assemblies consisting of acetylene-linked bisporphyrins with a 4-nitrophenylethynyl substituent and with a phenylethynyl substituent were synthesized. The Q-band of the phenylethynyl-substituted compound appears at 762 nm whereas that of the 4-nitrophenylethynyl-substituted one was red-shifted to 784 nm and intensified. This may be attributed to the participation of the nitro group in the π-electronic communication system. HOMOs and LUMOs were calculated for these compounds using an INDO/S-CI method. The effective two-photon absorption cross-section values of these self-assemblies were measured by using a nanosecond open aperture Z-scan method. The maximum effective two-photon absorption cross-section values of 4-nitrophenylethynyl- and phenylethynyl-substituted bisporphyrins were obtained as 1.2 × 105 GM and 8.1 × 104 GM , respectively, at 890 nm. A 1.5 enhancement factor was obtained by introducing nitro groups, which was similar to the value previously reported for ferrocene- and fullerene-connected supramolecular porphyrin.

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