This collaborative experimental research program will use femtosecond laser pulses focused to intensities of 10^17 - 10^19 Watts per square centimeter to examine the high intensity nonlinear optical properties of droplets. The PI's intend to answer the question of how light at relativistic intensity interacts with particles comparable in size to the light's wavelength. The interaction will be probed by measuring (a) the electron energy spectrum and hard x-ray emission that result from it, and (b) the high order harmonic generation that results from the nonlinear polarizability created when electrons are strongly driven around the particles. A variety of prepulse techniques will be employed to control the level of ionization on the particle surface and its plasma scale length. Ultimately, the experiments proposed here will study light-matter interactions that take place when the matter consists of particles that have been fabricated to respond resonantly with the irradiating field. The broader impact of the program will significantly add to the scope and number of research opportunities available to physics students at Harvey Mudd, and will support the education of graduate students at U.T. Austin.
