Femtosecond Pulse Propagation through Au and Ag Nanowires

Abstract

We examine the pulse reshaping of femtosecond pulses propagating through the fundamental surface plasmon polariton mode guided along Au and Ag nanowires. It is observed that the contribution of loss dispersion of the mode to the total dispersion is extremely significant and might exceed the contribution of the group velocity dispersion. In the case of Ag nanowires, beyond a certain critical wavelength, depending on the initial pulse width, a characteristic propagation distance is shown to exist, at which the pulse broadening is zero and up to which the pulse gets compressed instead of broadened. A simple analytical expression for zero dispersion distance is also derived giving its dependence on the initial pulse width. The study should find applications in selecting the wavelength of operation, initial pulse width, and the parameters of Au and Ag nanowires used in connection with ultra-short pulse propagation.