Impact of Chirped Pulses on Multidimensional Coherent Spectroscopy

Multidimensional Coherent Spectroscopy (MDCS) is a powerful technique for probing structure, nonlinear optical properties, ultrafast dynamics, and many-body interactions in a wide range of materials. Standard models often assume excitation with delta-function pulses, neglecting the effects of finite pulse duration and chirp. In this work, we extend the theoretical description of MDCS by incorporating chirped pulses into the optical Bloch equations in the interaction picture. We show that the relative time ordering of high- and low-frequency components within a pulse produces qualitatively different outcomes, significantly altering peak amplitudes, particularly in double-quantum 2D spectroscopy. Our results highlight the importance of accounting for realistic pulse characteristics in both the interpretation and design of multidimensional spectroscopy experiments.