Pump-Push-Probe for Ultrafast All-Optical Switching: The Case of a Nanographene Molecule

TL;DR

This paper demonstrates the use of pump-push-probe spectroscopy for ultrafast all-optical switching in a stable graphene nanostructure, highlighting its potential for advanced photonic applications.

Contribution

It introduces the application of PPP spectroscopy to a new, highly stable graphene molecule, showing its effectiveness for ultrafast optical switching in conjugated systems.

Findings

Successful optical switching of DBOV achieved

DBOV exhibits high environmental and photostability

Potential for integration into photonic devices

Abstract

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.