This repository includes two datasets included in the study "Dynamics of Collective Modes in an unconventional Charge Density Wave system BaNi2As2". Two datasets are included: Temperature_dependent_reflectivity_changes.dat Fluence_dependent_reflectivity_changes_at 10K.dat Temperature_dependent_reflectivity_changes.dat contain photoinduced reflectivity transients, recorder on BaNi2As2 for sample temperatures between 13 K and 149K. The first column is time-delay, other columns are the corresponding photoinduced reflectivity traces recorded at respective temperatures (constant fluence of 0.4 mJ cm−2). Fluence_dependent_reflectivity_changes_at 10K.dat contain photoinduced reflectivity transients, recorder on BaNi2As2 at 10 K. The first column is time-delay, other columns are the corresponding photoinduced reflectivity traces recorded at respective fluences. Each signal has been normalized to the respective fluence.