Inverse Raman effect
About: Inverse Raman effect is a(n) research topic. Over the lifetime, 25 publication(s) have been published within this topic receiving 601 citation(s).
21 Aug 1972
Abstract: 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.
Abstract: Spectroscopy on a picosecond time scale is shown to be feasible by a new technique. Inverse Raman spectra are obtained when the intense continuous spectrum of a self-phase modulated picosecond pulse is coincident in liquid and solid samples with an intense 5300 A picosecond laser pulse.
TL;DR: It appears that CARS spectroscopy, with its advantageous fluorescence rejection, can be usefully applied to biological samples by exploiting resonance enhancement, and the wavelength dependence of CARS is evidently steeper.
Abstract: Coherent anti-Stokes Raman scattering (CARS) spectra have been obtained for ferrocytochrome c and cyano cobalamin in aqueous solution at millimolar concentrations, using a pair of tunable dye lasers pumped by a pulsed nitrogen laser. Resonance enhancement was obtained by tuning the omega1 laser to the visible absorption bands of the samples. The spectral features correspond to those observed in the conventional resonance Raman spectra. It appears that CARS spectroscopy, with its advantageous fluorescence rejection, can be usefully applied to biological samples by exploiting resonance enhancement. While the background scattering from water is 10 times higher than that of benzene and other aromatic solvents, it is actually at the low end of the scale for most liquids. The anomalously low background of aromatic liquids is thought to result from competition by the unusually efficient stimulated Raman scattering which they display. Off-resonance spectra for both cobalamin and cytochrome c contain negative peaks, i.e., absorption bands in the background. These are interpreted as inverse Raman processes induced by the omega1 photons in the presence of the continuum provided by the background scattering. While both CARS and the inverse Raman effect are subject to resonance enhancement, the wavelength dependence of CARS is evidently steeper.
Abstract: The inverse Raman effect extends the general applicability of Raman spectroscopy to unstable species, fluorescing compounds and low pressure gases. A critical examination of the theory leads to optimization of the experimental variables. Interference effects from two-photon absorption processes are discussed. An experimental apparatus based on a giant-pulse ruby laser and a broad-band laser-pumped dye laser is described. Experimental correlations with ordinary Raman scattering cross sections are presented. The effects of inhomogeneous laser beams on the measurements are examined.