  We consider the coupling of an electromagnetic wave to a split-ring Josephson
oscillator or radio-frequency SQUID in the hysteretic regime. This device is
similar to an atomic system in that it has a number of steady states. We show
that one can switch between these with a suitable short external microwave
pulse. The steady states can be characterized by their resonant lines which are
of the Fano type. Using a static magnetic field, we can shift these spectral
lines and lift their degeneracy.
