Ultrafast lasers produce pulses of light at extremely regular intervals (about 13 nanoseconds apart) that are less than a picosecond in duration. These lasers allow us to study very fast phenomena in crystals and solid nanostructures. The work that my group at Vassar does involves using these lasers to generate and detect ultrasound that is roughly 1,000 times higher in frequency than traditional medical or industrial ultrasound. Since ultrasound can serve as a nondestructive probe of the size or mechanical properties of buried structures, this so called “picosecond ultrasound” should be a great way to study and image the nanoscale structures that form the backbone of all of our modern electronic devices. In this talk, Professor Daly will describe a number of investigations (some very applied, some very fundamental) that we have pursued over the past decade with this optical experiment.