▎ 摘　　要

We experimentally study the temporal dynamics of amplitude-modulated laser beams propagating through a water dispersion of graphene oxide sheets in a fiber-to-fiber U-bench. Nonlinear refraction induced in the sample by thermal effects leads to both phase reversing of the transmitted signals and dynamic hysteresis in the input output power curves. A theoretical model including beam propagation and thermal lensing dynamics reproduces the experimental findings. (C) 2015 Optical Society of America