Wavelength-dependent resonant homodyne and heterodyne transient grating spectroscopy with a diffractive optics method: Solvent effect on the third-order signal

A simplified diffractive optics method was used to study wavelength-dependent homodyne and heterodyne transient grating (TG) on a resonant system. Similar longtime dacay was observed in the real and imaginery components of the third-order molecular polarization at different excitation wavelengths. The wavelength dependence of the initial dynamics in homodyne TG and other four-wave mixing techniques was explained in terms of the interference of the wavelength-dependent resonant solute contributions with the nonresonant solvent contribution.