Managing light in nonlinear disordered media

We discuss different aspects of nonlinear effects in quadratic photonic structures with disordered domain distribution and random size. These kinds of materials with an irregular nonlinear multi-domain structure enables simultaneously phase matching mechanism of various parametric processes over an ultra-broad spectral range and in different spatial directions. The specific features of disordered domain structure greatly affect the emission pattern of the generated harmonics and thus. The recorded second harmonic pattern characterizes the size and degree of disorder in nonlinear photonic structures. On the other side, the transverse second harmonic generation, possible in these materials, provides a simple and robust single-shot method for ultrashort optical pulse characterization, which enables not only the estimation of the temporal width of the pulses but also the observation of their temporal evolution during propagation.