From femtosecond temporal spectroscopy to the potential by a direct classical inversion method
A simple procedure is described for the inversion of femtosecond temporal spectra to yield the potential. From observations by the femtosecond probe laser of the vibrational oscillations resulting from the coherent excitation of several vibrational states by the femtosecond pump laser over a range of excitation wavelengths (λ_1), one ascertains the energy dependence of the vibrational period τ. A fit of the data points τ(λ_1) is used in an analytical representation of a classical expression for the turning-point difference ΔR, from which one obtains V(ΔR) directly, without concern for the vibrational level structure. The method is applied to I_2(B ^3Π_(0+u)).