Ultrafast molecular photophysics in the deep-ultraviolet

In the landscape of ultrafast spectroscopic tools, the deep- and near-ultraviolet ranges (200–400 nm) have lagged behind due to the lack of tunability of both the pump and the probe pulses in this range. With the advent of novel nonlinear optical methods, this has now become possible. In this perspective, I will review some of the recent studies in the 250–400 nm range on (bio)chemical systems in order to stress the capabilities of ultrafast deep-UV spectroscopy to unravel new phenomena. This will serve as a basis to dwell on the promise and the new directions not only for molecular systems but also materials in solid or nanostructured form.