Craig McIntyre

Self pulsing solitons: A base for optically controllable pulse trains in photonic networks?

The dynamics of a broad-area vertical-cavity surface-emitting laser (VCSEL) with frequency-selective feedback supporting bistable spatial solitons is analyzed experimentally and theoretically. Self-pulsing is observed and indicates at least partial mode-locking of several external-cavity modes. It is argued that mode-locking of spatial solitons is an interesting and viable way to achieve three-dimensional, spatio-temporal self-localization and that these results give preliminary indications of a cavity light bullet component in the dynamics, though probably on a significant background. A possible application might be optically controllable, parallel carrier pulse trains on demand for all-optical processing in photonic networks.

Frequency and phase locking of laser cavity solitons

Self-localized states or dissipative solitons have the freedom of translation in systems with a homogeneous background. When compared to cavity solitons in coherently driven nonlinear optical systems, laser cavity solitons have the additional freedom of the optical phase. We explore the consequences of this additional Goldstone mode and analyze experimentally and numerically frequency and phase locking of laser cavity solitons in a vertical-cavity surface-emitting laser with frequency-selective feedback. Due to growth-related variations of the cavity resonance, the translational symmetry is usually broken in real devices. Pinning to different defects means that separate laser cavity solitons have different frequencies and are mutually incoherent. If two solitons are close to each other, however, their interaction leads to synchronization due to phase and frequency locking with strong similarities to the Adler-scenario of coupled oscillators.

Frequency and phase locking in a cavity soliton laser

The last few years have seen rapid progress in the creation of cavity solitons in broad-area semiconductor lasers. Such states represent small coherent microlasers which can be controlled by the operator thus making them interesting for optical information processing [1]. Here we investigate Laser Cavity Solitons (LCS) in a Vertical Cavity Surface Emitting Laser (VCSEL) with Frequency Selective Feedback (FSF). In our cavity soliton laser, the phase is not fixed and each LCS can have a different frequency due to disorder. Each LCS therefore has the freedom to choose its own frequency and phase. As such, it seems an interesting question to ask whether two or more of these self-localized states show frequency and phase locking behavior.

Mode-locked laser cavity solitons

The cavity soliton laser, based on a Vertical Cavity Surface Emitting Laser (VCSEL) with Frequency Selective Feedback (FSF) was recently realized both experimentally and theoretically (see [1] for a full review). Lasing does not occur over the whole aperture, rather it occurs on filaments which are much smaller than the aperture and which are stabilized by diffraction and nonlinearity. Hence they are referred to as Laser Cavity Solitons (LCS). They represent coherent individual emitters, i.e. microlasers, and may have different frequencies due to disorder. Here we present a demonstration of LCS mode-locking both numerically and experimentally. Mode-locked LCS have important applications in optical memories and in information processing.

Self-pulsing dynamics in a cavity soliton laser

The dynamics of a broad-area vertical-cavity surface-emitting laser (VCSEL) with frequency-selective feedback supporting bistable spatial solitons is analyzed experimentally and theoretically. The transient dynamics of a switch-on of a soliton induced by an external optical pulse shows strong self-pulsing at the external-cavity round-trip time with at least ten modes excited. The numerical analysis indicates an even broader bandwidth and a transient sweep of the center frequency. It is argued that mode-locking of spatial solitons is an interesting and viable way to achieve three-dimensional, spatio-temporal self-localization and that the transients observed are preliminary indications of a transient cavity light bullet in the dynamics, though on a non negligible background.

All-optical delay line with a cavity soliton laser

It has previously been established that cavity solitons (CS) can be created and erased in a vertical cavity surface emitting laser (VCSEL) with optical injection [1]. CS are ideal candidates for the implementation of information processes such as delay lines and optical memories in broad area optoelectronic devices. For example, an all-optical delay line in a VCSEL below threshold has recently been demonstrated [2]. In such a device, CS are written by an input pulsed signal, moved (i.e. delayed) transversally by phase gradients and read at the end of the line. We investigate here the dynamic and merging properties of CS in above threshold VCSELs with optical injection, with the aim of developing an all-optical delay line with a CS laser.

Locking and merging of Cavity Solitons

Cavity Solitons (CS) are ideal candidates for the implementation of information processes such as delay lines and optical memories in broad area optoelectronic devices. All-optical delay lines in vertical cavity surface emitting lasers operated below threshold have recently been demonstrated [1]. In such devices, CS are written by an input pulsed signal, move transversally following phase gradients, and are read at the end of the line to reconstruct the now delayed original signal. We investigate here the locking and merging properties of CS in a nonlinear Kerr cavity when the holding beam displays a spatially modulated phase.