  We experimentally investigate the nonlinear dynamics of two coupled fiber
ring resonators, coherently driven by a single laser beam. We comprehensively
explore the optical switching arising when scanning the detuning of the
undriven cavity, and show how the driven cavity detuning dramatically changes
the resulting hysteresis cycle. By driving the photonic dimer
out-of-equilibrium, we observe the occurrence of stable self-switching
oscillations near avoided resonance crossings. All results agree well with the
driven-dissipative Bose-Hubbard dimer model in the weakly coupled regime.
