Search

We report the existence of vectorial dark dissipative solitons in optical cavities subject to a coherently injected beam. We assume that the resonator is operating in a normal dispersion regime far from any modulational instability. We show that the vectorial front locking mechanism allows for the stabilisation of dark dissipative structures. These structures differ by their temporal duration and their state of polarization. We characterize them by constructing their heteroclinic snaking bifurcation diagram showing evidence of multistability within a finite range of the control parameter., Comment: \copyright 2021 Optical Society of America. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reserved

We investigate the dynamics of a ring cavity made of photonic crystal fiber and driven by a coherent beam working near to the resonant frequency of the cavity. By means of a multiple-scale reduction of the Lugiato-Lefever equation with high-order dispersion, we show that the dynamics of this optical device, when operating close to the critical point associated with bistability, is captured by a real order parameter equation in the form of a generalized Swift-Hohenberg equation. A Swift-Hohenberg equation has been derived for several areas of nonlinear science such as chemistry, biology, ecology, optics, and laser physics. However, the peculiarity of the obtained generalized Swift-Hohenberg equation for photonic crystal fiber resonators is that it possesses a third-order dispersion. Based on a weakly nonlinear analysis in the vicinity of the modulational instability threshold, we characterize the motion of dissipative structures by estimating their propagation speed. Finally, we numerically investigate the formation of moving temporal localized structures often called cavity solitons.

Driven Kerr resonators support temporal cavity solitons (CS) in the form of short optical pulses propagating along the cavity. They are also called localized structures and have been theoretically predicted in [1] and experimentally observed in [2]. They are often generated in the sub-critical modulation instability regime. The generation of CSs and their connections to optical comb generation have been recently reviewed [3]. They possess potential applications as bits in all-optical buffers and coherent optical frequency combs.

We consider a photonic crystal fiber resonator , driven by a coherent beam. The threshold for appearance of dark localized structures is estimated analytically and numerically by using a weakly nonlinear analysis in the vicinity of the modulational instability threshold. The nonlinear analysis allows to determine the parameter regime where the transition from supercritical to subcritical modulational instability takes place. This transition determines the threshold associated with the formation of dark cavity solitons. Numerical simulations of the governing model equation are in good agreement with the analytical results.

Summary form only given. Localized structures often called cavity solitons in optics have been observed in various systems of nonlinear science such as chemistry, physics, plant ecology and optics [1]. Scalar cavity solitons have been reported in the broad area [2] and in medium size vertical cavity surface emitting lasers [3]. The polarization degree of freedom was not considered in these works.In this communication, we investigate experimentally and theoretically the polarization state of cavity solitons in broad area vertical cavity surface emitting lasers under linearly polarized optical injection when varying optical injection linear polarization direction. These measurements show that the cavity soliton polarization state is not exactly the one of the optical injection. In fact, the polarization state of the generated cavity solitons is not linear, as it acquires distinct ellipticity [4]. We have built an experimental setup for generation and characterization of vector localized structures in the transverse section of a broad area VCSEL. Bistability corresponding to the spontaneous appearance and disappearance of a localized structure has been observed (as in Fig. 1), as a function of optical injection power. The Stokes parameters of these localized structures have been measured, for orientations of the optical injection linear polarization varying in a 90deg span. This analysis revealed that cavity solitons acquired ellipticity.

We theoretically investigate a weakly birefringent all-fiber cavity subject to linearly polarized optical injection. We describe the propagation of light inside the cavity using, for each linear polarization component of the electric field, the Lugiato-Lefever model. These two components are coupled by cross-phase modulation. We show that, for a wide range of parameters, there is a coexistence between a homogeneous steady state and two different types of temporal vector cavity solitons, which can be hosted in the same system. They differ by their polarization state and peak intensity. We construct their bifurcation diagram and show that they are connected through a saddle-node bifurcation. Finally, we show that vector cavity solitons exhibit multistability involving different polarization states with different energies.

Broad area Vertical-Cavity Surface-Emitting Lasers (VCSELs) have peculiar polarization properties which are a field of study by itself. These properties have already been used for localized structure generation, in a simple configuration, where only one polarization component was used. Here, we present new experimental and theoretical results on the complex polarization behavior of localized structures generated in an optically-injected broad area VCSEL. A linear stability analysis of the spin-flip VCSEL model is performed for the case of broad area devices, in a restrained and experimentally relevant parameter set. Numerical simulations are performed, in one and two dimensions. They reveal existence of vector localized structures. These structures have a complex polarization state, which is not simply a linear polarization following the one of the optical injection. Experimental results confirm theoretical predictions. Applications of this work can lead to the encoding of small color images in the polarization state of an ensemble of localized structures at the surface of a broad area VCSEL.

We study the formation of three-dimensional structures in type-I intracavity second harmonic generation model where polarization degrees of freedom due to the birefringence of the x(2) crystal is not considered. The device consists of an optical cavity filled with a quadratic nonlinear material and driven by an external beam at the fundamental frequency. The transmitted part of this field is coupled into the cavity where it undergoes second harmonic conversion. These dissipative structures consist of regular or localized 3D lattices of bright spots travelling at the group velocity of light in the material. We show evidence of stable three dimensional structures such as stripes and cylinders.

We report the experimental observation of two-dimensional vector cavity solitons in a Vertical-Cavity Surface-Emitting Laser (VCSEL) under linearly polarized optical injection when varying optical injection linear polarization direction. The polarization of the cavity soliton is not the one of the optical injection as it acquires a distinct ellipticity. These experimental results are qualitatively reproduced by the spin-flip VCSEL model. Our findings open the road to polarization multiplexing when using cavity solitons in broad-area lasers as pixels in information technology., SCOPUS: ar.j, info:eu-repo/semantics/published

We consider a broad area vertical-cavity surface-emitting laser(VCSEL) subject to injection and to time-delayed feedback. We present analytical and numerical analysis of the dependence of the drift instability threshold and on the feedback strength, feedback phase, and carrier relaxation time. we demonstrate that due to finite carrier relaxation rate the delay induced drift instability can be suppressed to a certain extent. We give analytical estimation of the soliton velocity near the drift instability point which is in a good agreement with numerical results obtained using the full model equations.

We consider a broad area vertical-cavity surface-emitting laser (VCSEL) subject to optical injection. We experimentally investigate the spontaneous formation of a Cavity Soliton (CS) in a medium size (80mum diameter) VSCEL. CSs are generated and erased when sweeping optical injection power and proper frequency detuning between the master laser and the VCSEL is set.

We report experimental evidence of spontaneous formation of localized structures in a 80 mu m diameter Vertical-Cavity Surface-Emitting Laser (VCSEL) biased above the lasing threshold and under optical injection. Such localized structures are bistable with the injected beam power and the VCSEL current. We experimentally investigate the formation of localized structures for different detunings between the injected beam and the VCSEL, and different injection beam waists. (C) 2014 Optical Society of America

Localized structures or localized patterns often called cavity solitons are nonlinear stationary bright or dark pulses in spatially extended systems. They have been observed in the transverse section of coherently driven nonlinear optical resonators. They attract a growing interest due to their potential application for all optical control of light. When they are well separated from each other, cavity solitons are independent or randomly distributed in the transverse plane. However, when they are close one to another they start to interact via their oscillating, exponentially decaying tails. This interaction leads to clustering phenomenon. This behavior is relatively well understood. So far however, the inclusion of delay feedback in the dynamics of spatially extended systems is relatively a new area of research.

We consider a broad area vertical-cavity surface-emitting laser (VCSEL) subject to injection and to time-delayed feedback. We show that near the nascent optical bistability regime, the space-time dynamics of this device is described by a generalized Swift-Hohenberg equation with delay. We classify different regime of stability of the homogeneous steady states in terms of dynamical parameters. We show that the delay modifies strongly the stability domain of both periodic and localized structures solutions. Finally, we show that the delay feedback induces a spontaneous motion of bright peaks in one and in two-dimenional transverse plane. Bifurcation diagram associated with these localized structures is constructed.

We investigate a control of the motion of localized structures of light by means of delay feedback in the transverse section of a broad area nonlinear optical system. The delayed feedback is found to induce a spontaneous motion of a solitary localized structure that is stationary and stable in the absence of feedback. We focus our analysis on an experimentally relevant system namely the Vertical-Cavity Surface-Emitting Laser (VCSEL). In the absence of the delay feedback we present experimental evidence of stationary localized structures in a 80 $\mu$m aperture VCSEL. The spontaneous formation of localized structures takes place above the lasing threshold and under optical injection. Then, we consider the effect of the time-delayed optical feedback and investigate analytically the role of the phase of the feedback and the carrier lifetime on the self-mobility properties of the localized structures. We show that these two parameters affect strongly the space time dynamics of two-dimensional localized structures. We derive an analytical formula for the threshold associated with drift instability of localized structures and a normal form equation describing the slow time evolution of the speed of the moving structure., Comment: 7 pages, 5 figures

We consider a broad area vertical-cavity surface-emitting laser(VCSEL) subject to injection and to time-dealyed feedback. We show that near the nascent optical bistability regime, the space-time dynamics of this device is described by a generalized Swift-Hohenberg equation with delay. We classify different regime of stability of the homogeneous steady states in terms of dynamical parameters. We show that the delay modifies strongly the stability domain of both periodic and localized structures solutions. Finally, we show that the delay feedback induces a spontaneous motion of bright peaks in one and in two-dimensional transverse plane. Bifurcation diagram associated with these localized structures is constructed.

We investigate the space-time dynamics of a Vertical-Cavity Surface-Emitting Laser (VCSEL ) subject to optical injection and to delay feedback control. Apart from their technological advantages, broad area VCSELs allow creating localized light structures (LSs). Such LSs, often called Cavity Solitons , have been proposed to be used in information processing, device characterization, and others. After a brief description of the experimental setup, we present experimental evidence of stationary LSs. We then theoretically describe this system using a mean field model. We perform a real order parameter description close to the nascent bistability and close to large wavelength pattern forming regime. We theoretically characterize the LS snaking bifurcation diagram in this framework. The main body of this chapter is devoted to theoretical investigations on the time-delayed feedback control of LSs in VCSELs. The feedback induces a spontaneous motion of the LSs, which we characterize by computing the velocity and the threshold associated with such motion. In the nascent bistability regime, the motion threshold and the velocity of moving LSs depend only on the feedback parameters. However, when considering the previously introduced mean-field model, theoretical predictions indicate that both motion threshold and velocity are strongly affected by the phase of the delay and by the carrier relaxation rate.

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.