Abstract: A spectroscopic measuring apparatus (100) being configured for measuring a spectral response of a sample (1), in particular a biological sample, comprises a fs laser source device (10) being arranged for an irradiation of the sample (1) with a sequence of probe light pulses (2) having a primary spectrum, a detector device (20) being arranged for a temporally and/or spectrally resolved detection of response light pulses (2?) having an altered spectrum and/or temporal structure and resulting from an interaction of the probe light pulses (2) with the sample (1), and a pulse modification device (30) comprising at least one quantum cascade laser (31 . . . 3N), wherein the pulse modification device (30) is configured to modify at least one of the probe light pulses (2) and the response light pulses (2?) by amplifying one or more spectral components of the at least one of the probe light pulses (2) and the response light pulses (2?) with the at least one quantum cascade laser (31 . . . 3N).