The Riemann problem in nonlinear fiber optics

We investigate theoretically and experimentally the Riemann problem in nonlinear fiber optics, i.e. how a pulse with stepwise change in power or/and chirp evolve along an optical fiber in the nonlinear regime. Our experiments reveal the formation of optical rarefaction waves and dispersive shock waves, which emerge in different combinations depending on the chosen initial condition, in excellent agreement with theory. We show that the results are interpretable in terms of canonical problems for standard fluids, i.e. the dam-breaking problem for shallow water and the piston problem for gas dynamics.