Nanoscale topography of dynamic surfaces with ultrafast time resolution

We describe an optical system for detecting the movement of a surface with subnanosecond temporal and nanometer vertical displacement resolution. The system is fielded on an experiment to determine the distortion of a laser-ablated metal layer and compare the results with hydrodynamic simulations. We also discuss errors that can arise and potential means to mitigate them. The resultant data show one can examine dynamic changes to a reflective surface with accuracy down to tens of nanometers at hundreds of picoseconds time resolution.