Multistable and Time Sequencing Photorefractive Ring Resonators

In this presentation we discuss and demonstrate the performance of two novel multimode photorefractive systems. The first is a multimode resonator with “winner-takes-all” dynamics. The resonator has several (in our case five) stable steady state solutions in which one mode always oscillates while all the others are suppressed. The system makes a decision which of the modes it will support depending on the initial conditions. The state of the system can then be switched with an external light signal. A modification of the resonator results in a different all-optical system which is capable of recalling a stored sequence of oscillating modes. The dynamics of this sequential recall process is again completely controlled by photorefractive two beam coupling.