The advent of femtosecond laser in the field of solid state physics has been at the origin of many discoveries. For instance, in the field of magnetism it was possible to understand how fwmtosecond optical demagnetizationcan probe the exchange interaction in ferromagnetic metals. The core of the project is to explore how optically generated acoustic waves interact with magnetization of a thin film, and vice versa, how femtosecond demagnetization can lead to longitudinal and shear acoustic waves exitation from release of magnetostrictive stresses. The later relevant physical framework is known as direct magnetostriction, which is the property of ferromagnetic material that causes them to change their shape or dimentions during the process of magnetization/demagnetization. Te revers phenomenon appears when an applied exterlal stress modifies statically or dynamically the magnetization configuration of a ferromagnet. A number of novel physical phenomena can be expected to arise when an ultrafast acoustic pulse, exited through absorption of a femtosecond laser pulse in a photoacoustic transducer, is injected through a ferromagnetic sample.