  In the last two decades, the three-beams pump-push-probe (PPP) technique has
become a well-established tool for investigating the multidimensional
configurational space of a molecule, as it permits to disclose precious
information about the multiple and often complex deactivation pathways of the
excited molecule. From the spectroscopic point of view, such a tool has
revealed details about the efficiency of charge pairs generation and
conformational relaxation in p-conjugated molecules and macromolecules. In
addition, PPP has been effectively utilised for modulating the gain signal in
conjugated materials by taking advantage of the spectral overlap between
stimulated emission and charge absorption in those systems. However, the
relatively low stability of conjugated polymers under intense photoexcitation
has been a crucial limitation for their real employment in plastic optical
fibres (POFs) and for signal control applications. Here, we highlight the role
of PPP for achieving ultrafast all-optical switching in p-conjugated systems.
Furthermore, we report new experimental data on optical switching of a newly
synthesised graphene molecule, namely dibenzo[hi,st]ovalene (DBOV). The
superior environmental and photostability of DBOV and, in general, of graphene
nanostructures can represent a great advantage for their effective applications
in POFs and information and communications technology.
