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Collisional broadening, line shifting, and line mixing in the stimulated Raman 2ν2 Q branch of CH4 J. Chem. Phys. 95, 7938 (1991); 10.1063/1.461322 Rotationally inelastic rates for N2-N2 system from a scaling theoretical analysis of the stimulated Raman Q branch J. Chem. Phys. 89, 5568 (1988); 10.1063/1.455563Rotational collisional narrowing in the NO fundamental Q branch, studied with cw stimulated Raman spectroscopyThe fundamental isotropic Raman Q branch of oxygen at pressures up to 2 atm and for temperatures between 295 and 1350 K has been recorded using stimulated Raman gain spectroscopy (SRGS) for collisions with oxygen and nitrogen. The line broadening and line shifting coefficients have been determined for several rotational quantum numbers (up to N = 55 at 1350 K). The temperature dependence of these coefficients has also been studied for most of the rotational lines. The line parameters (widths and shifts) have been then calculated a priori through a semiclassical model. A good agreement between experimental and theoretical data has been observed. Another theoretical approach based on fitting and scaling law has been used to calculate the line broadening coefficients. It is shown that a modified exponential energy gap model (MEG) and an energy corrected sudden law (ECS) for the state-to-state rotationally inelastic rates, account for the rotational and temperature dependences of the observed line widths. With regard to the energy corrected sudden law, the best results are obtained when the basis rate constants are modeled with a hybrid exponentialpower fitting law (EP). The line broadening and shifting coefficients of the oxygen-nitrogen mixture are very close to those found for pure oxygen.

In this paper, creation of pulse doublets and pulse trains by spectral phase modulation of ultrashort optical pulses is investigated. Pulse doublets with specific features are generated through step-like and triangular spectral phase modulation, whereas sequences of pulses with controllable delay and amplitude are produced via sinusoidal phase modulations. A temporal analysis of this type of tailored pulses is exposed and a complete characterization with the SPIDER technique (Spectral Phase Interferometry for Direct Electric-field Reconstruction) is presented.