We are addressing the need for better understanding of the mechanical effects involved in the femtosecond laser processing of transparent materials. By focusing infrared (1.03μm) laser pulses with a duration of 360fs and an energy of ~1μJ inside the bulk of a fused silica cube, we generate a plasma that absorbs laser energy. We then use a time-resolved microscope-polariscope based on a pump-and-probe scheme to measure optical transmission and stress-induced birefringence. Our methodology provides a link between initial ionization stages and the hydrodynamic response of the excited material thus allowing a full description of the interaction until the nanosecond timescale.