The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Yuen-ron Shen - One of the best experts on this subject based on the ideXlab platform.
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Optically Active Sum Frequency Generation Microscopy For Cell Imaging
Ultrafast Phenomena XV, 2007Co-Authors: Kai Zhang, Haw Yang, Yuen-ron ShenAbstract:Optically active Sum-Frequency Generation microscopy was applied to imaging cells, utilizing the intrinsic chirality of DNA and RNA molecules as the contrast mechanism.
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Three-dimensional chiral imaging by Sum-Frequency Generation.
Journal of the American Chemical Society, 2006Co-Authors: Kai Zhang, Haw Yang, Yuen-ron ShenAbstract:A Sum-Frequency Generation (SFG) microscope that is sensitive toward molecular chirality was demonstrated for the first time. Optically active images of chiral 1,1‘-bi-2-naphthol solutions were obtained with submicron spatial resolution. Three-dimensional sectioning capability of our microscope was also demonstrated. This optically active SFG microscopy can potentially become a powerful imaging technique for biological samples.
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Resonant Sum-Frequency Generation in chiral liquids
Optical Materials, 2002Co-Authors: Mikhail A. Belkin, T. A. Kulakov, Karl-heinz Ernst, S.h Han, Yuen-ron ShenAbstract:Sum-Frequency Generation in chiral liquids is conclusively demonstrated. Enhancement through both electronic and vibrational resonances is observed, providing a novel spectroscopic method for probing molecular chirality. Although the process is electric-dipole allowed, the signal strength is rather weak. This can be understood from the physical mechanism that leads to the chiral nonlinearity.
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Doubly-resonant Sum-Frequency Generation spectroscopy for surface studies
Chemical Physics Letters, 2002Co-Authors: Markus B. Raschke, Michitoshi Hayashi, S. H. Lin, Yuen-ron ShenAbstract:Abstract Doubly-resonant infrared–visible Sum-Frequency Generation (DR-SFG) as a two-dimensional surface spectroscopy was demonstrated experimentally for the first time. Probing electronic and vibrational transitions of a surface molecular monolayer simultaneously, the technique gives access to information about the electron-vibration coupling of the surface molecules. It allows selective studies of any interface accessible by light.
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Sum-Frequency Generation in Chiral Liquids near Electronic Resonance
Physical review letters, 2001Co-Authors: Mikhail A. Belkin, Sophia Han, Xing Wei, Yuen-ron ShenAbstract:We demonstrate experimentally that visible-visible Sum-Frequency Generation in the bulk of a chiral liquid is observable near electronic resonant transitions. Although the process is electric dipole allowed, it is rather weak because the orientational average over molecules effectively reduces the bulk chiral nonlinearity.
Steven Baldelli - One of the best experts on this subject based on the ideXlab platform.
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Multicolor Chemical Imaging by Sum Frequency Generation Imaging Microscopy of Monolayers on Metal Surfaces
The Journal of Physical Chemistry C, 2020Co-Authors: Aleksandr A. Pikalov, Daniela Rodriguez, Han Ju Lee, T. Randall Lee, Steven BaldelliAbstract:Sum frequency Generation imaging microscopy (SFG-IM) is a unique surface-specific technique that can detect the spatial distributions of differing monolayer species based on chemical contrast. Here...
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Chemical Microscopy of Surfaces by Sum Frequency Generation Imaging
The Journal of Physical Chemistry C, 2009Co-Authors: Katherine Cimatu, Steven BaldelliAbstract:Sum frequency Generation imaging microscopy has been developed and implemented in different systems from self-assembled monolayer on metal surfaces to reaction of a metal surface upon exposure to a...
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SUM FREQUENCY Generation INVESTIGATION OF GLYCEROL/WATER SURFACES
The Journal of Physical Chemistry B, 1997Co-Authors: Steven Baldelli, And Cheryl Schnitzer, Mary Jane Shultz, D. J. CampbellAbstract:The OH and CH regions of glycerol/water mixtures in the concentration range 0.0−1.0 mole fraction have been investigated with vibrational sum frequency Generation. Glycerol is found to partition to the surface of these solutions in all concentrations. Neat glycerol surfaces contain no free OH groups projecting into the vapor. The surface orientation of glycerol is constant through most of the concentration range.
Eric O. Potma - One of the best experts on this subject based on the ideXlab platform.
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Rapid hyperspectral, vibrationally resonant Sum-Frequency Generation microscopy
Multiphoton Microscopy in the Biomedical Sciences XVII, 2017Co-Authors: Adam M. Hanninen, Eric O. PotmaAbstract:We discuss the development and application of a laser-scanning, nonlinear optical microscope capable of generating vibrationally resonant images based on Sum-Frequency Generation (SFG), coherent anti-Stokes Raman scattering (CARS) or third-order Sum-Frequency Generation (TSFG). The combination of these three modalities allows vibrationally sensitive imaging of both χ (2) and χ (3) -active structures in biological tissues, addressing both Raman-active as well as IR-allowed vibrational modes. We show the practical utility of these vibrationally sensitive modalities by imaging collagen I rich tissues.
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Advances in Vibrationally Resonant Sum-Frequency Generation Microscopy
Optics in the Life Sciences Congress, 2017Co-Authors: Eric O. PotmaAbstract:Vibrationally resonant Sum-Frequency Generation microscopy is a member of the family of nonlinear optical microscopy techniques. It enables chemically selective imaging of non-centrosymmetric structures. We present the latest advances in this field.
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Molecular imaging with Sum-Frequency Generation microscopy
CLEO: 2015, 2015Co-Authors: Yang Han, Julie Hsu, Eric O. PotmaAbstract:We present an overview of the recent developments and biological imaging applications of Sum-Frequency Generation (SFG) microscopy.
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Molecular Imaging with Sum-Frequency Generation Microscopy
Optics in the Life Sciences, 2015Co-Authors: Julie Hsu, Adam Haninnen, Eric O. PotmaAbstract:We compare the imaging properties of polarization resolved Sum-Frequency Generation (SFG) microscopy with the imaging capabilities of second harmonic Generation (SHG).
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rapid vibrational imaging with sum frequency Generation microscopy
Optics Letters, 2011Co-Authors: Varun Raghunathan, Yang Han, Olaf Korth, Eric O. PotmaAbstract:We demonstrate rapid vibrational imaging based on sum frequency Generation (SFG) microscopy with a collinear excitation geometry. Using the tunable picosecond pulses from a high-repetition-rate optical parametric oscillator, vibrationally selective imaging of collagen fibers is achieved with submicrometer lateral resolution. We furthermore show simultaneous SFG and second harmonic Generation imaging to emphasize the compatibility of the microscope with other nonlinear optical modalities.
Victor Volkov - One of the best experts on this subject based on the ideXlab platform.
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Tip-induced deformation of a phospholipid bilayer: theoretical perspective of sum frequency Generation imaging.
The Journal of chemical physics, 2014Co-Authors: Victor VolkovAbstract:The paper addresses theory of Sum Frequency Generation imaging of an atomic force microscopy tip-induced deformation of a bilayer phospholipid membrane deposited over a pore: known as a nano-drum system. Image modeling employed nonlinearities of the normal modes specific to hydrocarbon terminal methyls, which are distributed about the deformed surfaces of inner and outer leaflets. The deformed profiles are according to the solutions of shape equation for Canham-Helfrich Hamiltonian accounting properties of four membranes, which differ in elasticity and adhesion. The results indicate that in continuous deformed surfaces, the difference in the curvature of the outer and inner leaflets dominates in the imaged nonlinearity. This is different comparing to the results for a perfect bilayer spherical cap system (the subject of previous study), where nonlinear image response is dominated by the mismatch of the inner and outer leaflets’ surface areas (as projected to the image plane) at the edge of perfectly spherical structure. The results of theoretical studies, here, demonstrate that Sum Frequency Generation imaging in continuous and deformed bilayer surfaces are helpful to address curvature locally and anticipate mechanical properties of membrane. The articles discuss applicability and practical limitations of the approach. Combination of Atomic Force Microscopy and Sum Frequency Generation imaging under controlled tip-induced deformation provides a good opportunity to probe and test membranes physical properties with rigor of adopted theory.
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Sum frequency Generation image reconstruction: Aliphatic membrane under spherical cap geometry
The Journal of chemical physics, 2014Co-Authors: Victor VolkovAbstract:The article explores an opportunity to approach structural properties of phospholipid membranes using Sum Frequency Generation microscopy. To establish the principles of sum frequency Generation image reconstruction in such systems, at first approach, we may adopt an idealistic spherical cap uniform assembly of hydrocarbon molecules. Quantum mechanical studies for decanoic acid (used here as a representative molecular system) provide necessary information on transition dipole moments and Raman tensors of the normal modes specific to methyl terminal – a typical moiety in aliphatic (and phospholipid) membranes. Relative degree of localization and frequencies of the normal modes of methyl terminals make nonlinearities of this moiety to be promising in structural analysis using Sum Frequency Generation imaging. Accordingly, the article describes derivations of relevant macroscopic nonlinearities and suggests a mapping procedure to translate amplitudes of the nonlinearities onto microscopy image plane according to geometry of spherical assembly, local molecular orientation, and optical geometry. Reconstructed images indicate a possibility to extract local curvature of bilayer envelopes of spherical character. This may have practical implications for structural extractions in membrane systems of practical relevance.
Sheng Hsien Lin - One of the best experts on this subject based on the ideXlab platform.
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A Theoretical Investigation of Surface-enhanced Sum-Frequency Generation
Journal of the Chinese Chemical Society, 2015Co-Authors: Y. L. Yeh, J. Lei, S. Y. Chen, A. H. H. Chang, Chi-hsiung Lin, Sheng Hsien LinAbstract:Following the surface enhanced Raman scattering (SERS), we shall investigate the possibility of observing surface-enhanced Sum-Frequency Generation (SESFG), which refers to the transformation of ordinary vibrational SFG (i.e. singly resonant) into SESFG. Two mechanisms of SESFG will be studied; one is due to the transformation of singly-resonant vibrational SFG into doubly resonant vibrational SFG (that is, both vibrationally resonant and Raman-scattering resonant) and the other is due to the enhancement of the polarizability in addition to the original vibrational resonance in vibrational SFG.
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Theoretical Formulation and Simulation of Electronic Sum-Frequency Generation Spectroscopy
The Journal of Physical Chemistry C, 2013Co-Authors: Chih-kai Lin, Michitoshi Hayashi, Sheng Hsien LinAbstract:Sum-Frequency Generation (SFG) spectroscopy is a powerful tool for not only identifying molecular species but also analyzing orientation configurations on a surface/interface. In this Article, we p...
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Vibrational sum frequency Generation of aqueous solutions of alcohol
CLEO Pacific Rim 2003. The 5th Pacific Rim Conference on Lasers and Electro-Optics (IEEE Cat. No.03TH8671), 1Co-Authors: Yuh-lin Yeh, Tai-huei Wei, Jung-yaw Huang, Sheng Hsien LinAbstract:We measured vibrational spectra of the surface of alcohol (C/sub n/H/sub 2n+1/, n=1 to 3) and water as a binary mixture via sum frequency Generation (SFG) in the OH region at the interface between air and liquid phases. Our results conform to a statement that the proportion of water molecules with a free dangling OH bond is about 29 percent at the interface between air and water. We have also demonstrated that a LiNbO/sub 3/ crystal containing -OH can be sufficient for the SFG spectroscopy measurement in OH region regardless of its absorption dip.
