Twin spotlight beam generation in quadratic crystals

Optical rogue waves have been extensively studied in the past two decades. However, observations of multidimensional extreme wave events remain surprisingly scarce. In this work we present the experimental demonstration of the spontaneous generation of spatially localized two-dimensional beams in a quadratic nonlinear crystal, which are composed by twin components at the fundamental and the second-harmonic frequencies. These localized spots of light emerge from a wide background beam, and eventually disappear as the laser beam intensity is progressively increased.Optical rogue waves are the optical counterpart of sudden and dramatic oceanic wave formations the underlying physics of which are thought to be connected with solitons. Here, the authors report the observation of a 2D spatial twin spotlight beam in anisotropic crystals with quadratic nonlinearity, that spontaneously appears and disappears as a function of laser beam in intensity.