Photoinduced Structural Dynamics in Laser-Heated Nanomaterials of Various Shapes and Sizes

Abstract

We examined photoinduced ultrafast structural dynamics such as coherent acoustic waves in many shapes of fcc metallic nanomaterials. Experimental data of nanosized thin films, prisms, spheres, rods, disks and pyramids from transient optical absorption/reflectance measurements were analyzed based on a combined Fermi-Pasta-Ulam model and two-temperature model. This work elucidates the structural dynamics induced by femtosecond laser heating, its size and shape effects on the period and phase of the excited acoustic phonon modes.