Fast Spinning-Top Dynamics of Photorefractive Grating

摘要

The photorefractive grating along with the two coupled waves produce a rich spatiotemporal dynamics such as those of solitons and chaos. In this paper, we relate this dynamics to that of a spinning top where the photorefractive coupling constant is large or more importantly the photorefractive dynamics is much faster than the photorefractive response time of the material. The solutions are in the form of Jacobi's Elliptic functions where their periods interestingly depend on the boundary and initial conditions. In a special case, the solutions are not periodic and are described in the form of hyperbolic functions. In this study we also encountered two conservations laws: one was expected, namely, the total pump and probe intensity is constant. The other is that the sum of the weighted pump intensity and the grating magnitude is constant.