FWM Implementation and Analysis Using MATLAB - Optical Signal Processing by Silicon Photonics - page 118

Fig. 9.6 Conversion efficiency profiles at different wavelengths against pump power
Fig. 9.7 Conversion efficiency evolution at different wavelength detuning values ( Wp - Ws ), Wp
is pump wavelength and Ws is signal wavelength
9.4 Waveguide Length, Pulse Width, and Repetition Rate
The pump pulse-width and repetition rate showed noticeable impact on free car-
rier density and hence the conversion efficiency. Higher the repetition rate and
wider the pump pulses results in lowering the CE. The propagation of the pulse
in the waveguide is governed by the interplay of the linear dispersion and nonlin-
earity. These effects can be described in terms of waveguide characteristic lengths
namely the GVD length, the TOD length, and the nonlinear length. The nonlinear
length of a silicon waveguide is seen to be several orders of magnitude shorter