Dynamic Characterization and Impulse Response Modeling of Amplitude and Phase Response of Silicon Nanowires

Amplitude and phase dynamics of silicon nanowires were measured using time-resolved spectroscopy. Time shifts of the maximum phase change and minimum amplitude as a function of pump power due to saturation of the free-carrier density were observed. A phenomenological impulse response model used to fit the experimental data indicated that the free-carrier lifetime was between 7.5 ≤ τ fc ≤ 16.2 ns, and the two-photon absorption coefficient and the Kerr coefficient were 3 × 10 -12 m.W -1 and 4 ×10 -18 m -18 .W -1 , respectively, for silicon nanowires with lengths varying from 3.6 to 14.9 mm.