Holographic solitons in centrosymmetric photorefractive dissipative systems

It is shown theoretically that the signal beam alone can evolve into steady-state bright and dark holographic solitons in a centrosymmetric photorefractive dissipative system that includes two balances, i.e., loss is exactly compensated by gain and diffraction is compensated by nonlinearity resulting from both self-phase modulation self-focusing and holographic focusing. These solitons have fixed amplitude and width. When the absorption of the system is neglected and the pump beam is switched to a background light, these solitons can become the “traditional” photorefractive solitons with arbitrary amplitude.