https://www.jidonline.org/article/S0022-202X(15)41173-X/pdf

In vivo confocal Raman microspectroscopy of the skin: Noninvasive determination of molecular concentration profiles

Coherent Raman imaging techniques have evolved to become powerful tools for biomedical imaging without the need for labelling.

Chemically sensitive bioimaging with coherent Raman scattering

Resonance Raman spectra are obtained when the wave number of the exciting radiation is close to, or coincident with, that of an electronic transition of the scattering species. Such spectra are usually characterized by a very large enhancement of the intensities of particular Raman bands, sometimes with the appearance of intense overtone and combination tone progressions. The technique provides detailed information about excited electronic states because it is only the vibrational modes associated with the chromophore that are resonance-Raman active. Additionally, the high sensitivity is such that compounds at concentrations as low as 10−6 mol/L may be detected, enabling resonance Raman spectroscopy to be used as an analytical tool and for the study of chromophores in molecules of biological interest.

Resonance Raman Spectroscopy, and Its Application to Inorganic Chemistry. New Analytical Methods (27)

High intensity Raman interactions

This paper and paper I in this series [P.H. Berens and K.R. Wilison, J. Chem. Phys. 74, 4872 (1981)] indicate that infrared and Raman rotational and fundamental vibrational–rotational spectra of dense systems (high pressure gases, liquids, and solids) are essentially classical, in that they can be computed and understood from a basically classical mechanical viewpoint, with some caveats for features in which anharmonicity is important, such as the detailed shape of Q branches. It is demonstrated here, using the diatomic case as an example, that ordinary, i.e., nonresonant, Raman band contours can be computed from classical mechanics plus simple quantum corrections. Classical versions of molecular dynamics, linear response theory, and ensemble averaging, followed by straightforward quantum corrections, are used to compute the pure rotational and fundamental vibration–rotational Raman band contours of N2 for the gas phase and for solutions of N2 in different densities of gas phase Ar and in liquid Ar. The evolution is seen from multiple peaked line shapes characteristic of free rotation in the gas phase to single peaks characteristic of hindered rotation in the liquid phase. Comparison is made with quantum and correspondence principle classical gas phase spectral calculations and with experimental measurements for pure N2 and N2 in liquid Ar. Three advantages are pointed out for a classical approach to infrared and Raman spectra. First, a classical approach can be used to compute the spectra of complex molecular systems, e.g., of large molecules, clusters, liquids, solutions, and solids. Second, this classical approach can be extended to compute the spectra of nonequilibrium and time‐dependent systems, e.g., infrared and Raman spectra during the course of chemical reactions. Third, a classical viewpoint allows experimental infrared and Raman spectra to be understood and interpreted in terms of atomic motions with the considerable aid of classical models and of our well‐developed classical intuition.

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Molecular Dynamics and Spectra. II. Diatomic Raman.

I. Interaction of Light and Matter, The Raman Scattering Tensor.- I-1. Electromagnetic Radiation of an Oscillating Dipole.- I-2. Higher Order Moments: Quadrupoles and Magnetic Dipoles.- I-3. Spectroscopic Transitions.- I-4. Classical Considerations of the Radiation Field and Quantum Mechanical Calculation of the Induced Dipole Moment, the Correspondence Principle.- I-5. Formulation of the Scattering Tensor.- I-6. Symmetry of the Scattering Tensors.- II. Properties of Tensors.- II-1. Vectors and Dyadics.- II-2. Scattering Tensors and Radiation from Classical Oscillators.- II-3. Rotation of Tensors.- II-4. Specific Rotation of Symmetric and Antisymmetric Tensors.- III. Some Aspects of Group Theory.- III-1. Symmetry Elements.- III-2. Definition Properties of Point, Space and Factor Groups.- III-3. Representations of Groups.- III-4. Transformation Properties of the Scattering Tensor.- III-5. Irreducible Tensors and Their Transformation Properties.- III-6. The Scattering Operator.- IV. The Normal Raman Effect.- IV-1. Theory of the Electronic Raman Effect.- IV-2. Electronic Levels and Selection Rules.- IV-3. Normal Modes, Normal Coordinates and Vibrational Wave Functions.- IV-4. Theory of the Vibrational Raman Effect.- IV-5. The Case of Degenerate Electronic States.- IV-6. Rotational Levels and Wave Functions.- IV-7. The Rotational Raman Effect.- IV-8. Depolarization Ratios.- V. Other Scattering Processes.- V-l. The Hyper Raman Effect.- V-2. The Stimulated Raman Effect.- V-3. Induced Absorption: The Inverse Raman Effect.- V-4. The Resonance Raman Effect.- Appendix I. Properties of Representations of Some Important Point Groups.

J. A. Koningstein

Papers

Introduction to the Theory of the Raman Effect