Finite pulse effects in single and double quantum spectroscopies

When modeling experimental 2D spectra, the effects of finite pulse durations are usually neglected to optimize computational costs. We present an analytic treatment of finite pulse duration effects on electronic 2D spectra. While the photon echo signal is more robust, the double quantum signal shows unexpected dependencies, based on mixing of absorptive and dispersive components. In the limit of Lorentzian pulse shapes, we compare the exact results of our analytically solvable approach to standard approximations made for finite pulse effects. We show how these approximations fail to reproduce the correct phase and amplitudes of vibrational oscillations.