In the last decade silicon on insulator – based waveguides have progressively attracted the attention of the nonlinear-optics research community. Due to the strong refractive index contrast of such waveguides and thanks to the very high nonlinear refractive index of silicon, strong nonlinear effects can be achieved in SOI structures, even at moderate pump power level (e.g. P < 1 mW) . However, silicon also exhibits a very strong nonlinear absorption coefficient that severely limits the waveguide performance at power level above 1 mW. Very recently nonlinear AlGaAs waveguides were demonstrated, showing both efficient continuous wave and pulsed nonlinearities  with no two-photon absorption (TPA) effect, even at high power level.
© 2015 IEEEPDF Article