Ricerc@Sapienza

The most studied solution of the Helmholtz equation is, in the paraxial approximation, the Gaussian beam. This partial description of the optical propagation drastically reduces the possibility of optical schemes and imaging. Overcoming this limit is crucial to developing innovative devices. Although many studies have started to explore the field of non-paraxial optics, much still has to be developed and understood.
The aim of this project is to explore, experimentally and numerically, the behaviour of non-gaussian beams, such as Bessel, Airy, and vortex beams when these propagate in photorefractive crystals, with specific focus on samples at the phase transition from the paraelectric to the ferroelectric phase. The photorefractive nonlinearity is strong also with low intensity fields, so we can easily access the study of extreme events and we can observe the time dynamics of the system. Our preliminary results show that, using non-gaussian beams, new and exotic phenomena are observed.