Obtained if the photon flux incident on the sample is held constant. If the solution is sufficiently dilute that the fraction of the exciting radiation absorbed is proportional to the absorption coefficient of the analyte, and if the quantum yield is independent of the exciting wavelength, the corrected excitation spectrum will be identical in shape to the absorption spectrum.
Source:
PAC, 1984, 56, 231. 'Nomenclature, symbols, units and their usage in spectrochemical analysis-Part VI: molecular luminescence spectroscopy' on page 242 (https://doi.org/10.1351/pac198456020231)