Factorial Dynamic Pattern Memory in Globally Coupled Lasers

Recently, applicability of complex dynamics to information storage (memory) has been discussed in nonlinear optical systems. Spatial chaos memory was proposed in a bistable pixelsl1 and in a coupled bistable chain.2 Dynamic memory in a delayed feedback bistable system was demonstrated experimentally.3 On the other hand, Otsuka demonstrated that m a = (N − 1)! (N: number of oscillating modes) coexisting dynamical spatial patterns, i. e., antiphase periodic motions, can be selectively excited by applying seed signals to the modulated multimode lasers whose modes are globally coupled through spatial hole burning.4 In this paper, we discuss the detailed bifurcation scenario, featuring clustered states and chaotic itinerancy5 among destabilized clustered states. Also, factorial dynamical pattern memory associated with antiphase and clustered states as well as the effect of spontaneous emission on memory operation are demonstrated by numerical simulations.