Actively Induced Reflection via a Quadratic Nonlinear Optical Interaction in a Semiconductor Photonic Crystal: Application to Ultra Fast All-Optical Modulation and Switching

We show that using AlGaAs semiconductor as nonlinear material in a specific configuration of one dimensional periodic structure, we may actively induce important changes in the reflectivity of an optical beam. We show that a control beam at second harmonic frequency (0.77 mum) optically induces chances in the reflection coefficient of a signal at the fundamental frequency (1.55 mum), via the intrinsically fast second order nonlinear interaction between both pulses within the structure. The temporal duration of the change is only limited by the length of the pulse. This very fast effect may be used for the design of an ultra-fast all-optical modulator or switching device