  We discuss finite-difference time-domain simulations of femtosecond pulses
interacting with silver nanowires and nanoparticles. We show how localized hot
spots near the metal surfaces can be generated and controlled in a
spatiotemporal manner. The control is made possible by chirping the pulses such
that the effective frequency passes through surface plasmon resonances
associated with different spatial regions of the nanostructure over the course
of time. The response of such nanostructures to chirped pulses could provide a
novel means of encoding or decoding optical signals.
