Dynamics and interactions of cavity solitons in photonic devices

• Main Author: McIntyre, Craig
• Published: University of Strathclyde 2013
• Subjects: 530
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.576475

In this thesis, we present a theoretical and numerical study of the properties and dynamics of cavity solitons in photonic systems. Three systems are investigated - a semiconductor laser with optical injection, a semiconductor laser with frequency selective feedback and a nonlinear cavity with a Kerr material. Cavity solitons have common features which can be observed in all three systems as well as properties which are unique to each specific system. The writing and erasing process under the action of an external pump is characterised first leading to the establishment and subsequent erasure of stable cavity solitons in these systems. In general a coherent writing beam is used, although in the case of lasers with frequency selective feedback an incoherent writing beam is required. Switch-on time is measured, allowing for optimisation of the writing process. Cavity soliton drift is introduced by manipulating the detuning and, where appropriate, the phase of the optical in jection. Phase modulations of the optical injections are preferable as cavity solitons remain stable over a larger range of parameters, although this is not always possible. Cavity soliton interactions are particularly interesting, with collisions resulting in differing behaviour in each system, including locking, merging and the annihilation of the two cavity solitons. Furthermore Adler-type locking is shown for two cavity solitons pinned by localised defects in the detuning by varying the depth of one defect with respect to the other. Finally, oscillating and pulsing regimes of cavity solitons are investigated in the laser with frequency selective feedback. Unlocked oscillations and mode-locked oscillations and pulses are described with the possible observation of fully self localised three dimensional pulses or light bullets. The intriguing properties of cavity solitons investigated in this thesis can be of practical application in the realisation and optimisation of optical memories, optical delay lines and optical logic gates.