Extreme events in the dynamical behaviour of Nd:YVO4 laser with modulated losses: experimental approach

A. LACAPMESURE; N. MIRON; M.AGUERO; M. KOVALSKY; A. HNILO; J. TREDICCE

Buenos Aires

Workshop; XVII EscuelaGiambiagi; 2015

Departamento de Física, Universidad de Buenos Aires

Since optical rogue waves (ORWs) were first reported in 2007, the study of extreme events in optical systems has been a very active research field. In such systems,extreme events appear as high intensity pulses in the chaotic behaviour, giving a long tail in the probability distribution of the intensity of the pulses. Understanding the dynamics in which extreme events arise comprises the first step onward the prediction and control of these pulses. In this work, we study the dynamics of an all-solid-state Nd:YVO4 laser (class B) with electro-optically modulated losses. Taking the amplitude modulation as the adjustable control parameter V, we analyze the temporal series for the maxima of intensity pulses. At low values of V the intensity traces obtained were periodic, showing a monotonically increasing period, hysteresis and bistability. After reaching a threshold the system goes into a low-dimensional chaotic behaviour, in which the probability distribution of the temporal series presents a non-Gaussian shape. Extreme events arise as events in the long tail of the distribution at high amplitude values, we find a nonlinear dependence of their occurrence with the control parameter. These results are in good qualitative agreement with the existence of an ?external crisis?, as recent theoretical model predicts. Furthermore, we observe that the predictability horizon of the dynamics associated when extreme events occur is larger than the associated to a regular pulse. Therefore, we hypothesize the existence of structures within the chaotic behaviour in which the systems becomes more predictable.