Download or read book Tomographic State Reconstruction and Time Resolved Surface Enhanced Coherent Anti stokes Raman Scattering in the Single Molecule Limit written by Steven Yampolsky and published by . This book was released on 2014 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Time-resolved, surface-enhanced, coherent anti-Stokes Raman spectroscopy (tr-SECARS) is ideally suited for preparing and probing vibrational coherences in molecules. By enhancing the local response of a single molecule with a dipolar nano-antenna, vibrational dynamics have been measured at the single molecule limit. In contrast with tr-CARS measurements in ensembles, the vibrational coherence of a single molecule is not subject to pure dephasing. It exhibits characteristic phase and amplitude noise, which allows the statistical distinction between single, few, and many molecule sources to be determined. To build on the current work, by using three unique pulses to spectrally fiter the response of the molecule, the characteristic noise can be isolated and measured background-free. If the probing of a superposition state is carried out over a real resonance, then it is possible to tomographically reconstruct the complete description of quantum dynamics in phase space representation via the Wigner Distribution Function(WDF). The WDF can be reconstructed from either the wavepacket via Wigner Transform, or an experimentally measured density, via an Inverse Radon Transform. The calculations presented here highlight the necessary conditions in order to reconstruct the WDF with delity from a proposed experiment and compare the density derived WDF with that of the wavepacket. The principle is firstly demonstrated using a Kerr gated detection of emission from an evolving state on a bound harmonic potential energy surface. The model is then explained in the case of a proposed spectrally resolved transient grating experiment (SRTG). The WDFs generated from the limiting conditions show that the reproduction delity of the experimentally derived WDF are dependent on the probe, utilized to measure the evolving superposition, and the curvature, or the vibra tional frequency of the potential energy surfaces, and the dephasing time of the vibrational superposition states. Given two potentials, I show that it is possible to optimize probe pulse parameters to improve the delity of the state reconstruction. Due to the variational principle, the negative volume of the WDF, or the Wigner hole, can only be reduced via measurements - the pulse parameters can be optimized iteratively even when the molecular potentials are not known.
Download or read book Application of Highly Time resolved Coherent Anti stokes Raman Scattering to Chemical Dynamics written by David Lee Phillips and published by . This book was released on 1989 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Surface Enhanced Raman Scattering written by Richard Chang and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the course of the development of surface science, advances have been identified with the introduction of new diagnostic probes for analytical characterization of the adsorbates and microscopic structure of surfaces and interfaces. Among the most recently de veloped techniques, and one around which a storm of controversy has developed, is what has now been earmarked as surface enhanced Raman scattering (SERS). Within this phenomenon, molecules adsorbed onto metal surfaces under certain conditions exhibit an anomalously large interaction cross section for the Raman effect. This makes it possible to observe the detailed vibrational signature of the adsorbate in the ambient phase with an energy resolution much higher than that which is presently available in electron energy loss spectroscopy and when the surface is in contact with a much larger amount of material than that which can be tolerated in infrared absorption experiments. The ability to perform vibrational spectroscopy under these conditions would lead to a new understanding about the chemical identity, geome try, and bonding of adsorbed material at a level previously unacces sible. It is for these reasons that the last few years have brought an explosion of activity surrounding the exploitation of SERS. The search for the origines) of the anomalous enhancement has given rise to a research sub-activity of its own. Efforts to explain the en hancement have led to an increased understanding of the whole range of phenomena associated with the interaction of photons with adsor bates and metal surfaces.
Download or read book Towards Near field Single Molecule Surface Enhanced Raman Scattering Detection written by Li-Lin Tay and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The surface enhanced Raman scattering spectra of crystal violet and R6G and a number of colourless molecules adsorbed on silver colloid aggregates were studied as a function of power and position using a Raman microscope. The anti-Stokes signals of the dye molecules show line intensities much greater than the expected on the basis of the Boltzmann equilibrium population of the excited vibrational state. The large anti-Stokes intensities are attributed to the difference in Stokes and anti-Stokes Raman cross-sections resulting from pre-resonance or resonance Raman processes in the adsorbate-substrate complex rather than to optical pumping of molecular vibrational excited states as proposed by Kneipp and co-workers [Phys. Rev. Lett., 76, 2444, 1996]. Far-field imaging with a Raman microscope shows no significant inhomogeneity of the Raman enhancement in the images of the deposited self-affine silver colloid clusters down to spatial resolutions of I [mu]m2. A near-field scanning optical microscope (NSOM) operating with a shear-force feedback distance-control mechanism was employed to study the optical response of self-affine, deposited colloidal silver films. In the near-field region, NSOM is capable of an optical resolution down to 100 nm which is beyond the traditional diffraction limit of far field optics. Near-field Rayleigh microscopy with simultaneous topographic imaging indicates that the electromagnetic fields on the surface of the self-affine films are localized in regions smaller than the excitation wavelength. The pattern of high-field regions varies greatly with excitation wavelengths and does not correlate with topography. Local spectra of self-affine film showed distinct resonances arising with highly location-dependent frequencies. The most highly resolved of these resonances correspond to individual surface plasmon normal modes. Specific vibrational bands from the SERS spectra of plithalazine adsorbed on self-affine, silver colloid films were mapped over portions of the film surface in the near-field. The near-field Raman intensity maps display patterns of field localization in subwavelength regions. The pattern of field localization varies greatly with scattered wavelength. Observations in the near-field validate recent theories of the optical response of self-affine fractal objects [Phys. Report, 61, 272, 1996].
Download or read book Surface Enhanced Raman Scattering New Theoretical Approaches Materials and Strategies written by Ivano Alessandri and published by Frontiers Media SA. This book was released on 2020-03-25 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optics Letters written by and published by . This book was released on 2007 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Tip Enhancement written by Satoshi Kawata and published by Elsevier Science Limited. This book was released on 2007 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the recent advances in the area of near-field Raman scattering, mainly focusing on tip-enhanced and surface-enhanced Raman scattering. Some of the key features covered here are the optical structuring and manipulations, single molecule sensitivity, analysis of single-walled carbon nanotubes, and analytic applications in chemistry, biology and material sciences. This book also discusses the plasmonic materials for better enhancement, and optical antennas. Further, near-field microscopy based on second harmonic generation is also discussed. Chapters have been written by some of the leading scientists in this field, who present some of their recent work in this field. ·Near-field Raman scattering ·Tip-enhanced Raman spectroscopy ·Surface-enhanced Raman spectroscopy ·Nano-photonics ·Nanoanalysis of Physical, chemical and biological materials beyond the diffraction limits ·Single molecule detection
Download or read book Time Resolved Picosecond Pure Rotational Coherent Anti Stokes Raman Spectroscopy for Thermometry and Species Concentration in Combustion Environments written by and published by . This book was released on 2009 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Time Resolved Picosecond Pure Rotational Coherent Anti Stokes Raman Spectroscopy for Thermometry and Species Concentration in Flames written by and published by . This book was released on 2009 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Surface Enhanced Raman Scattering written by Richard Chang and published by . This book was released on 2014-01-15 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coherent Anti stokes Raman Spectroscopy written by Stanford University. Ginzton Laboratory and published by . This book was released on 1977 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Visualizing Chemistry written by National Research Council and published by National Academies Press. This book was released on 2006-06-01 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientists and engineers have long relied on the power of imaging techniques to help see objects invisible to the naked eye, and thus, to advance scientific knowledge. These experts are constantly pushing the limits of technology in pursuit of chemical imagingâ€"the ability to visualize molecular structures and chemical composition in time and space as actual events unfoldâ€"from the smallest dimension of a biological system to the widest expanse of a distant galaxy. Chemical imaging has a variety of applications for almost every facet of our daily lives, ranging from medical diagnosis and treatment to the study and design of material properties in new products. In addition to highlighting advances in chemical imaging that could have the greatest impact on critical problems in science and technology, Visualizing Chemistry reviews the current state of chemical imaging technology, identifies promising future developments and their applications, and suggests a research and educational agenda to enable breakthrough improvements.
Download or read book Surface Enhanced Raman Scattering written by Katrin Kneipp and published by Springer. This book was released on 2006-08-03 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: Almost 30 years after the first reports on surface-enhanced Raman signals, the phenomenon of surface-enhanced Raman scattering (SERS) is now well established. SERS gained particular interest after single-molecule Raman spectroscopy had been demonstrated. This book summarizes and discusses present theoretical approaches that explain the phenomenon of SERS and reports on new and exciting experiments and applications of the fascinating spectroscopic effect.
Download or read book Applications of High Resolution Coherent Anti Stokes Raman Scattering Spectroscopy written by Engelene t. H. Chrysostom and published by . This book was released on 2001 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Time resolved Surface Enhanced Raman Scattering Studies of Surface Photochemistry and Electrochemistry written by Wei Zhang and published by . This book was released on 1995 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Surface enhanced Raman Scattering of Nanostructured Assemblies written by Kyle W. Kimble and published by . This book was released on 2001 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electronic Resonance Enhanced Coherent Anti Stokes Raman Scattering Technique for Detection of Combustion Species and Biological Molecules written by Sherif Fayez Hanna and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
