Spontaneously moving solitons in a cavity soliton laser with circular section (original) (raw)
Related papers
Moving Solitons in a Cavity Soliton Laser
PIERS Online, 2009
We show that in a cavity soliton laser based on a VCSEL with a saturable absorber the solitons can spontaneously move. A key parameter ruling the dynamical instability is the ratio of the carrier lifetimes in the amplifier and in the absorber. The direction of the spontaneous motion is arbitrary but it can be controlled by injecting a low-intensity guiding beam for a short interval of time. The final velocity of the moving soliton is determined by the parameters of the system.
Cavity soliton laser based on a VCSEL with saturable absorber
Localized States in …, 2011
In this Chapter we intend to make a review on our work on cavity solitons in semiconductor lasers with saturable absorbers, with a special attention to the most recent results.We study theoretically a broad-area vertical cavity surface emitting laser (VCSEL) with a saturable absorber, and show numerically the existence of cavity solitons in the system: they exist as solitary structures superposed on a background with zero intensity. Therefore, this system can work as a cavity soliton laser, ensuring maximum contrast and compactness of the device, in comparison with other systems supporting cavity solitons. In particular, in absence of a holding beam, these solitons do not rely on a proper phase of the addressing pulses to be either created or deleted.We also show that the properties of the system are deeply influenced by the radiative recombination of carriers. Taking into account this process, the existence of solitons is shown numerically for a choice of parameters suitable to describe real devices, where the same material is used for the active and the passive parts. Furthermore, we compare three different switching techniques for the control of cavity solitons in a VCSEL based cavity soliton laser, one incoherent and the other two semicoherent with different injection frequencies. We show that the switching dynamics and energies can be very different depending on the type of injection. Finally, we show that in a cavity soliton laser based on a VCSEL with a saturable absorber the solitons can spontaneously move if the ratio of the carrier lifetimes in the amplifier and in the absorber takes appropriate values. The direction of the motion is arbitrary, while its velocity is determined by the parameters of the system. In devices with a finite cross section the CS describes different trajectories depending on the shape of the boundary of the pumped region. For a circular pump the CS moves on circular trajectories along the boundary. This dynamical regime can be exploited to create controllable trains of pulses, together with frequency and amplitude modulation.
2010
We consider a broad area Vertical-Cavity Surface Emitting Laser (VCSEL) operating below the lasing threshold and subject to optical injection and time-delayed feedback. We derive a generalized delayed Swift-Hohenberg equation for the VCSEL system which is valid close to the nascent optical bistability. We first characterize the stationary cavity soli-tons by constructing their snaking bifurcation diagram and by showing clustering behavior within the pinning region of parameters. Then we show that the delayed feedback induces a spontaneous motion of two-dimensional cavity solitons in an arbitrary direction in the transverse plane. We characterize moving cavity solitons by estimating their threshold and calculating their velocity. Numerical 2D solutions of the governing semiconductor laser equations are in close agreement with those obtained from the delayed generalized Swift-Hohenberg equation.
The European Physical Journal D, 2010
We consider a rate equation model describing broad area vertical-cavity surface-emitting lasers subject to injection and to time-delayed optical feedback. We show that the inclusion of an external cavity affects dramatically the space-time behavior of this system by modifying the instability threshold as well as the wavelength of the Turing instability. We show also that the delayed feedback is responsible for the appearance of traveling wave instability. Finally, we demonstrate that a single cavity soliton exhibits a spontaneous motion with a constant velocity. Without delayed feedback transition to the moving cavity soliton does not exist.
Cavity soliton laser based on VCSEL with saturable absorber
Applied Physics B-lasers and Optics, 2005
We study theoretically a broad-area vertical cavity surface emitting laser (VCSEL) with a saturable absorber. We show numerically the presence of cavity solitons in the system: they exist as solitary structures formed through a modulationally unstable homogeneous lasing state that coexists with a background with zero intensity. Such a peculiar scenario endows the solitons with unique properties compared to cavity solitons in most previously studied optical systems. In particular, these solitons do not as such rely on a proper phase of the addressing pulses to be either created or deleted. We show that exciting and deleting the solitons depend crucially on whether a threshold in the soliton peak has been reached.
Physical Review A, 2012
We consider a broad area vertical-cavity surface-emitting laser (VCSEL) operating below the lasing threshold and subject to optical injection and time-delayed feedback. We derive a generalized delayed Swift-Hohenberg equation for the VCSEL system, which is valid close to the nascent optical bistability. We first characterize the stationary-cavity solitons by constructing their snaking bifurcation diagram and by showing clustering behavior within the pinning region of parameters. Then, we show that the delayed feedback induces a spontaneous motion of two-dimensional (2D) cavity solitons in an arbitrary direction in the transverse plane. We characterize moving cavity solitons by estimating their threshold and calculating their velocity. Numerical 2D solutions of the governing semiconductor laser equations are in close agreement with those obtained from the delayed generalized Swift-Hohenberg equation.
The European Physical Journal D, 2010
We present recent experimental results on the control and dynamics of cavity solitons in a monolithic, vertical cavity surface emitting laser with saturable absorber. On one hand, the fast and independent manipulation of two laser cavity solitons is achieved and a flip-flop operation is demonstrated with a single control-beam. On the other hand, a pulsing localized structure is presented and we demonstrate the control of a pulsing multispot structure that we can switch-on and off. These results are promising in view of the obtainment of a pulsed and monolithic cavity soliton laser.
Reversible Motion of Cavity Solitons on Modulated Backgrounds
Nonlinear Guided Waves and Their Applications, 2005
Cavity solitons can move up or down phase gradients, or even remain motionless regardless of background modulations. Abrupt changes in their direction of motion and final destination occur on increasing the background modulation wavenumber. Arrays of spatially localized structures are of wide scientific interest in photonics [1]. Studies of the behavior of spatial solitons on inhomogeneous backgrounds have shown that the breaking of translational invariance leads to their motion [2, 3, 4, 5, 6]. For example, cavity solitons in nonlinear absorbers [2] and frequency converters [5, 6] move up phase gradients.