Bistable Phase Locking of a Nonlinear Optical Cavity via Rocking: Transmuting Vortices into Phase Patterns

Abstract

We report experimental observation of the conversion of a phase-invariant nonlinear system into a phase-locked one via the mechanism of rocking [de Valcárcel and Staliunas, Phys. Rev. E 67, 026604 (2003)]. This conversion results in that vortices of the phase-invariant system are being replaced by phase patterns such as domain walls. The experiment is carried out on a photorefractive oscillator in a two-wave mixing configuration. A model for the experimental device is given that reproduces the observed behavior.

Phase-bistable patterns and cavity solitons induced by spatially periodic injection into vertical-cavity surface-emitting lasers

“…That modulation must entail sign alternations (i.e., π -phase jumps) of the forcing in time (temporal rocking) or in space (spatial rocking) and must occur on sufficiently fast, nonresonant scales as compared to the typical scales of the oscillations' envelope dynamics. Theoretical [13][14][15][16][17][18][19] and experimental [16,20,21] studies have revealed that this type of forcing converts the initially phase-invariant oscillatory system into a phasebistable pattern forming one, similarly to the classic 2:1 resonant forcing (at twice the system's natural frequency) of a spatially homogeneous Hopf bifurcation [8,9]. The advantage of rocking with respect to the 2:1 resonance is that some systems (optical in particular) are insensitive to the latter, due to their extremely narrow frequency response.…”

Phase-bistable pattern formation in oscillatory systems via rocking: application to nonlinear optical systems

“…Clearly, such predictions must be contrasted with experiments and with theoretical studies of specific models. So far rocking has been investigated experimentally in photorefractive oscillators (PROs) [41,42], which are a kind of nonlinear optical systems, and in nonlinear electronic circuits [37,43], finding good agreement with the theoretical predictions. Both types of experiments have an oscillatory nature and exhibit phase invariance in the absence of external perturbations.…”

Phase-bistable Kerr cavity solitons and patterns

“…Rocking was initially proposed in the form of a sinusoidal, time-modulated additive signal to the complex Ginzburg-Landau (CGL) equation [44]-which is the simplest description of a laser and of any self-oscillatory system close to threshold-and later generalized to different forms of modulation, even random [45]. Such a kind of temporal rocking has been demonstrated experimentally in optical [46] and in electronic [45,47] systems. More recently spatial rocking has been proposed as a universal mechanism [48] and applied to special optical systems (semiconductor lasers) [49], where the injection is periodically modulated in space.…”