Two-dimensional filtering in the Fourier domain of transient grating coherent artifacts in time-resolved spectroscopy

Removal of coherent artifacts is important in the analysis of time and wavelength resolved spectroscopy data. By taking advantage of the strong correlation between spectra acquired sequentially in time, artifact removal can be formulated as a 2D problem for improved effectiveness. This paper proposes a 2D method to remove transient grating coherent artifacts from femtosecond time-resolved spectroscopy data based on filtering in the Fourier domain, leading to better estimation of the material parameters from the measured data. The method is simple, intuitive, and light on computation resources. The effectiveness of the method is demonstrated with experimental data acquired from a bare gold film with and without coherent artifacts using mutually parallel and perpendicular pump/probe polarizations, as well as with more complex samples (nanostructured gold film on a glass substrate and rhodamine fluorophores in solution). The proposed method is expected to be applicable to coherent artifact removal in other types of time and wavelength-resolved spectroscopy data. [Display omitted] •Coherent artifacts in time resolved spectroscopy, such as transient grating artifacts, distort experimental measurements.•Coherent artifact removal can be formulated as a two-dimensional numerical problem for greatly improved efficacy.•Fourier domain filtering can remove artifact distortions without significantly altering the underlying baseline data. The proposed artifact filtering method is demonstrated on data from metal nanostructures and fluorophores in solution.•The proposed method is applicable to other types of coherent artifacts in time and wavelength-resolved spectroscopy data.