Ultrabroadband transient absorption spectroscopy with sub-25 µOD sensitivity and double differential scatter and noise rejection.

Transient absorption spectroscopy is a powerful technique for studying charge transfer, energy conversion, and electron-phonon coupling in an array of chemical and material systems on the femtosecond to nanosecond timescales. Here, we describe a state-of-the-art ultrabroadband transient absorption spectrometer for solid samples, which achieves sub-50 fs time resolution and sub-25 µOD sensitivity across a wide spectral range, from 350 to 900 nm. Combined with suppression of pump pulse scatter, the high signal-to-noise ratio of this spectrometer allows investigating previously inaccessible phenomena in well studied samples, such as electron-phonon coupling signatures in transition metal oxides.