The Experts below are selected from a list of 243 Experts worldwide ranked by ideXlab platform
Hans Ågren - One of the best experts on this subject based on the ideXlab platform.
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Spectral profiles of Two-Photon Absorption : Coherent versus two-step Two-Photon Absorption
2020Co-Authors: Sergey Polyutov, Ivaylo Minkov, Faris Gel'mukhanov, Kenji Kamada, Alexander Baev, Hans ÅgrenAbstract:We present a theory of Two-Photon Absorption in solutions which addresses the, formation of spectral shapes taking account of the vibrational degrees of freedom. The theory is used to rationalize observed differences between spectral shapes of one- and Two-Photon Absorption. We elaborate Oil two underlying causes. one trivial and one non-trivial, behind these differences. The first refers simply to the fact that the set of excited electronic states constituting the spectra, will have different relative cross sections for one- and two- photon Absorption. The second reason is that the two-step and coherent Two-Photon Absorption processes are competing, making the one- and Two-Photon spectral bands different even considering a, single final state. The theory is applied to the N-101 molecule [di-phenyl-amino-nitro-stilbene] which was recently studied experimentally in the paper.
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Spectral profiles of Two-Photon Absorption: Coherent versus two-step Two-Photon Absorption
MRS Proceedings, 2020Co-Authors: Sergey Polyutov, Ivaylo Minkov, Faris Gel'mukhanov, Kenji Kamada, Alexander Baev, Hans ÅgrenAbstract:We present a theory of Two-Photon Absorption in solutions which addresses the formation of spectral shapes taking account of the vibrational degrees of freedom. The theory is used to rationalize observed differences between spectral shapes of one- and Two-Photon Absorption. We elaborate on two underlying causes, one trivial and one non-trivial, behind these differences. The first refers simply to the fact that the set of excited electronic states constituting the spectra will have different relative cross sections for oneand two- photon Absorption. The second reason is that the two-step and coherent Two-Photon Absorption processes are competing, making the oneand Two-Photon spectral bands different even considering a single final state. The theory is applied to the N-101 molecule [di-phenyl-amino-nitro-stilbene] which was recently studied experimentally in the paper [ T.-C. Lin, G.S. He, P.N. Prasad, and L.-S. Tan, J. Mater. Chem., 14, 982, 2004.]
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Two-Photon Absorption of Metal-Assisted Chromophores
Journal of Chemical Theory and Computation, 2014Co-Authors: Xin Li, Zilvinas Rinkevicius, Hans ÅgrenAbstract:Aiming to understand the effect of a metal surface on nonlinear optical properties and the combined effects of surface and solvent environments on such properties, we present a multiscale response theory study, integrated with dynamics of the Two-Photon Absorption of 4-nitro-4'-amino-trans-stilbene physisorbed on noble metal surfaces, considering two such surfaces, Ag(111) and Au(111), and two solvents, cyclohexane and water, as cases for demonstration. A few conclusions of general character could be drawn: While the geometrical change of the chromophore induced by the environment was found to notably alter (diminish) the Two-Photon Absorption cross section in the polar medium, the effects of the metal surface and solvent on the electronic structure of the chromophore surpasses the geometrical effects and leads to a considerably enhanced Two-Photon Absorption cross section in the polar solvent. This enhancement of Two-Photon Absorption arises essentially from the metal charge image induced enlargement of the difference between the dipole moment of the excited state and the ground state. The orientation-dependence of the Two-Photon Absorption is found to connect with the lateral rotation of the chromophore, where the Two-Photon Absorption reaches its maximum when the polarization of the incident light coincides with the long-axis of the chromophore. Our results demonstrate a distinct enhancement of the Two-Photon Absorption by a metal surface and a polar medium and envisage the employment of metal-chromophore composite materials for future development of nonlinear optical materials with desirable properties.
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Two‐Photon Absorption Cross‐Sections of Reference Dyes: A Critical Examination
ChemPhysChem, 2008Co-Authors: Yan-hua Wang, Hans ÅgrenAbstract:The electronic structure and one- and Two-Photon Absorption spectra of four fluorophores, p-bis(o-methoxystyryl)benzene (Bis-MSB), coumarin 307, fluorescein and rhodamine B, commonly used as reference compounds for Two-Photon Absorption spectra, have been theoretically calculated and compared with available experimental data. The possible reasons for the wide discrepancies in Two-Photon Absorption cross-sections reported in the literature are discussed on the basis of the theoretical findings. The role of a solvent environment on the electronic one- and Two-Photon Absorption spectra is also studied. We highlight some necessary precautions that one needs to take when comparing literature results of Two-Photon Absorption cross-sections.
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Two-Photon Absorption in five-membered heteroaromatic oligomers
Optics Communications, 1999Co-Authors: Patrick Norman, Hans ÅgrenAbstract:Structure-to-property relations for the Two-Photon Absorption intensities of oligothiophenes, oligopyrroles, and oligofurans have been studied using ab initio response theory. Power law dependences of the Two-Photon Absorption intensities with respect to the length of the oligomers have been revealed, and localization lengths at which the intensities are completely dominated by one single state are found.
Kenji Kamada - One of the best experts on this subject based on the ideXlab platform.
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Spectral profiles of Two-Photon Absorption : Coherent versus two-step Two-Photon Absorption
2020Co-Authors: Sergey Polyutov, Ivaylo Minkov, Faris Gel'mukhanov, Kenji Kamada, Alexander Baev, Hans ÅgrenAbstract:We present a theory of Two-Photon Absorption in solutions which addresses the, formation of spectral shapes taking account of the vibrational degrees of freedom. The theory is used to rationalize observed differences between spectral shapes of one- and Two-Photon Absorption. We elaborate Oil two underlying causes. one trivial and one non-trivial, behind these differences. The first refers simply to the fact that the set of excited electronic states constituting the spectra, will have different relative cross sections for one- and two- photon Absorption. The second reason is that the two-step and coherent Two-Photon Absorption processes are competing, making the one- and Two-Photon spectral bands different even considering a, single final state. The theory is applied to the N-101 molecule [di-phenyl-amino-nitro-stilbene] which was recently studied experimentally in the paper.
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Spectral profiles of Two-Photon Absorption: Coherent versus two-step Two-Photon Absorption
MRS Proceedings, 2020Co-Authors: Sergey Polyutov, Ivaylo Minkov, Faris Gel'mukhanov, Kenji Kamada, Alexander Baev, Hans ÅgrenAbstract:We present a theory of Two-Photon Absorption in solutions which addresses the formation of spectral shapes taking account of the vibrational degrees of freedom. The theory is used to rationalize observed differences between spectral shapes of one- and Two-Photon Absorption. We elaborate on two underlying causes, one trivial and one non-trivial, behind these differences. The first refers simply to the fact that the set of excited electronic states constituting the spectra will have different relative cross sections for oneand two- photon Absorption. The second reason is that the two-step and coherent Two-Photon Absorption processes are competing, making the oneand Two-Photon spectral bands different even considering a single final state. The theory is applied to the N-101 molecule [di-phenyl-amino-nitro-stilbene] which was recently studied experimentally in the paper [ T.-C. Lin, G.S. He, P.N. Prasad, and L.-S. Tan, J. Mater. Chem., 14, 982, 2004.]
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Two-Photon Absorption of hydrocarbons at visible wavelengths
Proceedings of SPIE, 2013Co-Authors: Kenji KamadaAbstract:The Two-Photon Absorption properties of brunched π-conjugated hydrocarbons at visible wavelengths, up to 400 nm measured by using the femtosecond open-aperture Z-scan method are presented. The hydrocarbons, phenylethynylsubstituted benzenes, shows moderate (several hundreds GM) or very large (~20,000 GM) Two-Photon Absorption cross sections, suggesting such a hydrocarbons can be efficient Two-Photon Absorption chromophores in the wavelength region.
Ulf Österberg - One of the best experts on this subject based on the ideXlab platform.
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Two‐photon Absorption and photoconductivity in photosensitive glasses
Journal of Applied Physics, 1996Co-Authors: Peter S. Weitzman, Ulf ÖsterbergAbstract:We have measured the two‐photon Absorption coefficent at 0.527 μm to be 1.8±0.4×10−3 cm/GW in a germanium‐doped silica fiber. Using Absorption and luminescence measurements we estimated the two‐photon Absorption coefficient at 1.053 μm to be smaller than 6×10−7 cm/GW. Using a capacitive technique we measured the photoconductivity to be approximately 6×10−9 1/Ω cm in the visible. The photoconductivity inreased linearly with intensity. A qualitative discussion of the defect dynamics related to photosensitive phenomena in optical glass fibers is given based on the experimental results.
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Two photon Absorption and photoconductivity in photosensitive glasses
Proceedings of LEOS'94, 1994Co-Authors: Peter S. Weitzman, Ulf ÖsterbergAbstract:In this paper we present experimental evidence for the creation of defects in Ge doped silica by exposure to intense visible or UV light. The presence of the defects is detected by an increase in two photon Absorption at 1053 nm and an increase in photoconductivity at 488 nm. This provides evidence to support models for photoinduced second harmonic generation based on interference between single photon Absorption of visible light and two photon Absorption of IR light. In as much as photoinduced SHG has been observed in many other glass systems, results from this paper can be generalized to provide a picture of photoinduced SHG in solid, centrosymmetric systems.
Keiji Tanaka - One of the best experts on this subject based on the ideXlab platform.
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Two-Photon Absorption spectroscopy of As2S3 glass
Applied Physics Letters, 2002Co-Authors: Keiji TanakaAbstract:Spectral dependence of Two-Photon Absorption in a chalcogenide glass, As2S3, has been studied using a tunable light source. The result shows that Two-Photon and two-step Absorptions occur, and the Two-Photon Absorption spectrum appears to be exponential. These results and roles of nonlinear processes in photoinduced phenomena are discussed.
Yi Chen - One of the best experts on this subject based on the ideXlab platform.
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Two-Photon Absorption Photochromic Optical Image Storage in Indoly-Benzylfulgimide/PMMA Film
Advanced Materials Research, 2013Co-Authors: Menke Neimule, Ying Li Wang, Lu Men Chao, Yi ChenAbstract:As one kind of organic photochromic optical storage material, fulgides are well-known for their thermally irreversibility. The Two-Photon Absorption 3D optical storage technology is one of the hot research topics in the field of high-density information storage. Using optical image storage technology the recording and reading rates can be improved. In this paper, it’s found that in one kind of 3-indoly-benzylfulgimide/PMMA film, there exits Two-Photon Absorption property. And depending on this property, the Two-Photon Absorption photochromic optical image storage was realized in an indoly-benzylfulgimide/PMMA film. It is proved that the N-benzyl-1,3,4-trimethyl-2-(2-methyl-) indoly-fulgimide has potential application in the Two-Photon Absorption 3D optical storage.
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two photon Absorption photochromic optical image storage in indoly benzylfulgimide pmma film
Advanced Materials Research, 2013Co-Authors: Menke Neimule, Ying Li Wang, Lu Men Chao, Yi ChenAbstract:As one kind of organic photochromic optical storage material, fulgides are well-known for their thermally irreversibility. The Two-Photon Absorption 3D optical storage technology is one of the hot research topics in the field of high-density information storage. Using optical image storage technology the recording and reading rates can be improved. In this paper, it’s found that in one kind of 3-indoly-benzylfulgimide/PMMA film, there exits Two-Photon Absorption property. And depending on this property, the Two-Photon Absorption photochromic optical image storage was realized in an indoly-benzylfulgimide/PMMA film. It is proved that the N-benzyl-1,3,4-trimethyl-2-(2-methyl-) indoly-fulgimide has potential application in the Two-Photon Absorption 3D optical storage.