Stokes Raman spectrum

Anti-Stokes picosecond TR spectra were also obtained with pump-probe time delays over the 0 to 10 ps range and selected spectra are shown in Figure 3.33. The anti-Stokes Raman spectrum at Ops indicates that hot, unrelaxed, species are produced. The approximately 1521 cm ethylenic stretch Raman band vibrational frequency also suggests that most of the Ops anti-Stokes TR spectrum is mostly due to the J intermediate. The 1521 cm Raman band s intensity and its bandwidth decrease with a decay time of about 2.5 ps, and this can be attributed the vibrational cooling and conformational relaxation of the chromophore as the J intermediate relaxes to produce the K intermediate.This very fast relaxation of the initially hot J intermediate is believed to be due to strong coupling between the chromophore the protein bath that can enable better energy transfer compared to typical solute-solvent interactions. ... 

Fig. 1. Stokes and anti-Stokes Raman spectrum of carbon tetrachloride...

Figure 10.3. Schematic experimental set-up for single-molecule SERS. Insert (top) shows a typical Stokes and anti-Stokes Raman spectrum. Insert (bottom) shows an electron microscope image of SERS-active colloidal clusters. (With permission from Ref. 21.)...

Figure 5 Vibrational spectra of neat liquid acetonitrile (ACN) (top) mid-IR spectrum (bottom) Stokes Raman spectrum using a conventional spectrometer (solid line). The dashed spectrum obtained with the ultrafast laser system has somewhat lower resolution (From Ref. [46].)...

Scan the Stokes Raman spectrum of CCI4 for shifts of 150 to 1000 cm from the exciting line.t Note that the frequency in wavenumbers is given by v (cm ) = 1/A = vie, where c is the speed of light in cm s Record both parallel and perpendicular polarization scans so that you can determine the depolarization ratio of aU bands. Indicate the spectrometer wavelength or wavenumber reading on the chart at several points in the scan to provide reference points for the determination of the Raman shifts for all bands. 

Figure 2.2-2 The visible, near, middle and far infrared region of the spectrum drawn in a scale linear in wavenumbers. The infrared (IR) and far-infrared (FIR) spectrum is recorded by absorption of light from a continuous spectrum in the range of A = 2.5. .. 100 pm = i) = 4000. .. 100 cm and A = 100. .. 1000 pm = 100. .. 10 cm". Raman spectra can be excited by monochromatic radiation, emitted by different lasers in the visible (VIS) or near-infrared range (NIR). Molecules emit Raman lines with a frequency difference AF to that of the exciting frequency >o between 0 and -f 4000 or - 4000 cm. Usually only the Raman spectrum which is shifted to. smaller wavenumbers, the Stokes Raman spectrum, is recorded. Its range is indicated by bars for different exciting lines Ar" " laser at 488 and 515 nm, HeNe laser at 623 nm, GaAs laser at 780 nm, and Nd YAG laser at 1064 nm.

Figure 5.9a shows a resonance anti-Stokes Raman spectrum of UV-irradiated SWNTs measured by using quasi-monochromatic excitation with the narrowband 790-mn beam (1.57 eV), containing information about the electron-phonon coupling in frequency domain. The characteristic Raman bands, G- and D-bands, were clearly observed. The relatively large D-band indicates the introduction of defects... 

Fig. 5.9 (a) Anti-Stokes Raman spectrum of SWNTs excited by the 790-nm narrowband pulses, (b) Time-frequency 2D-CARS spectra of the SWNTs. (c) Time-resolved CARS spectrum of SWNTs at 0.84 ps [32]... 

Fig. 6. Stokes Raman spectrum of Chlorella pyr. cells observed at room temperature during irradiation with 514.5 nm (19436 an 1) without additional background light (laser power 1.0 W)42)...

The complete Stokes Raman spectrum covering shifts in the range 10-3500 cnr1 can be obtained and the intensity of Raman scattering is directly proportional to the concentration of the scattering species, an important factor for quantitative analysis. However, the Raman effect is relatively weak and hence a... 

Figure 4.4. The Stokes and anti-Stokes Raman spectrum of sulphur at 1064 nm laser excitation. The feature between 9300 and 9394 cm is an experimental artefact due to the optical filter used to suppress the very intense Rayleigh band.

Figure 14 Simultaneous measurement of both the Stokes and anti-Stokes Raman spectrum of a 1 ym anatase (Ti02) film using the equipment diagrammed in Figure 5.

Figure 33 Anti-Stokes Raman spectrum of DLC films observed under the 1236-A excitation [73]. (Reproduced from Journal of Non-Crystalline Solids, 227-230, Ivanov-Omskii, V. I., et al.. Bonded and non-bonded hydrogen in diamond-like carbon, pp. 627-630. Copyright 1998, with permission from Elsevier-Science.)...

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