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.