  Symmetry and symmetry breaking of light states play an important role in
photonic integrated circuits and have recently attracted lots of research
interest that is relevant to the manipulation of light polarisation,
telecommunications, all optical computing, and more. We consider four-field
symmetry breaking within two different configurations of photonic dimer
systems, both comprised of two identical Kerr ring resonators. In each
configuration we observe multiple degrees and levels of spontaneous symmetry
breaking between circulating photon numbers and further, a wide range of
oscillatory dynamics, such as chaos and multiple variations of periodic
switching. These dynamics are of interest for optical data processing, optical
memories, telecommunication systems and integrated photonic sensors.
