Self-Induced Fractional Fourier Transform and Revivable Higher Order Spatial Solitons in Strongly Nonlocal Nonlinear Media

The fractional Fourier transform (FRFT) naturally exists in the strongly nonlocal nonlinear (SNN) media and the propagation of optical beams in SNN media can be simply regarded as a self-induced FRFT. Through FRFT technic the evolution of fields in SNN media can be conveniently dealt with and an arbitrary square-integrable input field presents generally as a revivable higher order spatial soliton which reconstructs its profile periodically after every 4 times of Fourier transforms. The self-induced FRFT would illuminate the prospect of the SNN media in new applications such as continuously tunable nonlinearity-induced FRFT devices.