Dynamics of thermalization in Au-Ti double-layered film excited by a femtosecond laser pulse

We theoretically investigate the dynamics of thermalization in Au-Ti double-layered film irradiated by a femtosecond laser pulse. A nonequilibrium thermal relaxation model is proposed to study the energy deposition and transport processes during femtosecond laser pulse heating of double-layered film. The maximum phonon temperature on the Au layer can be greatly adjusted by optimizing the thickness of the Au layer. In addition, the effect of Au-layer thickness on the thermalization dynamics of the Au-Ti system is examined in detail. This study provides a new way to increase the resistance of mirrors to thermal damage in applications of high-power lasers.