Ultrafast dynamics of femtosecond laser processing of bulk titanium nitride

Titanium nitride (TiN) is a multifunctional material with excellent optical, mechanical, and electrical properties, such as high hardness, superior thermal stability, excellent conductivity, and strong corrosion resistance. These characteristics make TiN widely applicable in fields such as optoelectronic devices, surface-enhanced Raman scattering (SERS) substrates, superconducting devices, and wear-resistant coatings. Femtosecond lasers, as a high-precision processing tool, offer ultrahigh peak power, ultrashort pulse duration, and minimal heat-affected zones, enabling highly accurate, three-dimensional controllable micro-nanofabrication. To date, femtosecond lasers have been successfully employed in the nanopatterning, microstructure fabrication, and optical property modulation of TiN films and bulk materials. Therefore, investigating the interaction mechanism between femtosecond lasers and TiN is of great significance for its optical functionalization and device fabrication. This study employs time-resolved pump-probe techniques to capture transient optical response data on femtosecond-picosecond-nanosecond timescales, analyzing ultrafast processes such as plasma dynamics, electron-phonon interactions, and phase transitions induced by femtosecond laser irradiation on TiN. The research reveals the ultrafast dynamics of near-infrared femtosecond laser interactions with TiN materials. Our findings provide valuable insights into using femtosecond lasers to manipulate the optical, electrical, and structural properties of TiN, thereby advancing its applications in plasmonic optics, photonic devices, and micro-nanofabrication.