Self phase modulation in highly nonlinear hydrogenated amorphous silicon

We study self phase modulation in submicron amorphous silicon-on-insulator waveguides. We extract both the real and imaginary part of the nonlinear parameter γ from a 1 cm long waveguide with a cross-section of 500×220nm². The real and imaginary part of the nonlinear parameter are found to be 767W^-1m^-1 and -28W^-1m^-1 respectively. The figure of merit (FOM) is found to be 3.6 times larger than the FOM in crystalline silicon (c-Si).