Intense, coherent lightwaves can drive materials into nonequilibrium states with properties that are inaccessible under equilibrium conditions. When electrons interact coherently with a periodic electric field, their energy bands can be reshaped through a mechanism known as Floquet engineering. This approach offers a promising route to modifying electronic properties and potentially inducing new topological phases of matter, including Floquet topological insulators. This internship aims to explore the potential of femtosecond mid-infrared pulses to coherently drive the topological crystalline insulator PbSnSe from a trivial phase into a light-induced Floquet topological phase. Using mid-infrared pump–THz probe spectroscopy, the candidate will track transient changes in the THz transmittance of thin PbSnSe layers and investigate how the response depends on the material bandgap and on the energy of the driving field, searching for signatures of light-induced topological states, potentially including a Dirac-like dispersion absent at equilibrium. In collaboration with Marco Schiro, the candidate will also contribute to developing a Floquet-based theoretical framework to interpret the measurements and characterize the transient electronic states. The internship can be continued as a PhD.