Imaging metallic multilayer structures through ultrafast optically driven quasiparticle transport

Summary form only given. It has recently been demonstrated that ultrashort excitation of quasiparticles by femtosecond laser pulses in thin metallic films leads to nonequilibrium particle dynamics and nonthermal transport. We report here on an advancement of this topic to demonstrate that these phenomena can be used to "image" otherwise hidden components of metallic multilayers. Specifically we report on the transport of nonequilibrium electrons through multilayers composed of AuTiAu films. The results are compared with a Au film deposited next to the multilayer film. The experimental observation of the fractional change in reflectivity is dependent on which component of the multilayer component (i.e., with or without Ti) is being integrated.