Physical mechanisms of nanostructuring ferromagnetic thin films and hybrid multilayers using single ultrashort laser pulses

Irradiation of ferromagnetic thin films and metal/ferromagnet bilayers with ultrashort (femtosecond or picosecond) laser pulses through an optically transparent substrate results in the formation of closed spallation or delamination cavities possibly enclosing ultrahigh vacuum. Physical properties of these structures are investigated by the optical interferometric, magneto-optical Kerr, atomic force and SEM microscopies and ultrafast optical pump-probe techniques. The topology of these cavities can be controlled through the laser pulse duration and/or the internal structure of irradiated films. Their remarkable acoustic and magneto-optical properties will be revealed as well.