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AbstractObjectivesThe goal is to develop clinical pharmacy in the Belgian hospitals to improve drug efficacy and to reduce drug-related problems.MethodsFrom 2007 to 2014, financial support was provided by the Belgian federal government for the development of clinical pharmacy in Belgian hospitals. This project was guided by a national Advisory Working Group. Each funded hospital was obliged to describe yearly its clinical pharmacy activities.ResultsIn 2007, 20 pharmacists were funded in 28 pilot hospitals; this number was doubled in 2009 to 40 pharmacists over 54 institutions, representing more than half of all acute Belgian hospitals. Most projects (72%) considered patient-related activities, whereas some projects (28%) had a hospital-wide approach. The projects targeted patients at admission (30%), during hospital stay (52%) or at discharge (18%). During hospital stay, actions were mainly focused on geriatric patients (20%), surgical patients (15%), and oncology patients (9%). Experiences, methods, and tools were shared during meetings and workshops. Structure, process, and outcome indicators were reported and strengths, weaknesses, opportunities, and threats were described. The yearly reports revealed that the hospital board was engaged in the project in 87% of the cases, and developed a vision on clinical pharmacy in 75% of the hospitals. In 2014, the pilot phase was replaced by structural financing for clinical pharmacy in all acute Belgian hospitals.ConclusionThe pilot projects in clinical pharmacy funded by the federal government provided a unique opportunity to launch clinical pharmacy activities on a broad scale in Belgium. The results of the pilot projects showed clear implementation through case reports, time registrations, and indicators. Tools for clinical pharmacy activities were developed to overcome identified barriers. The engagement of hospital boards and the results of clinical pharmacy activities persuaded the government to start structural financing of clinical pharmacy.

We study the nonlinear interaction of partially incoherent nonlinear optical waves. We show that, in spite of the incoherence of the waves, coherent phase effects may play a relevant role during the propagation, in contrast with the usual wave turbulence description of the interaction. These nonlinear phase effects may lead the system to unexpected processes of self-organization, such as condensation, or incoherent soliton generation in instantaneous response nonlinear media. Such self-organization processes may be characterized by a reduction of the non-equilibrium entropy, which violates the Boltzmann's H-theorem of entropy growth inherent to the wave turbulence theory.

In this work we present the observation of spatial optical solitons in liquid crystal cells by recording the diffraction pattern of the out-coupled beam on a distant screen. Simultaneously, the light propagation is observed via scattering measurements. The most important observation is displacement of the beam on the screen due to the transverse undulation inside the cell. This undulation is caused by the anisotropic walk-off of the beam. The displacement is in good agreement with the values of the undulation earlier reported.

We study the nonlinear interaction of partially incoherent nonlinear optical waves. We show that, in spite of the incoherence of the waves, coherent phase effects may play a relevant role during the propagation, in contrast with the usual wave turbulence description of the interaction. These nonlinear phase effects may lead the system to unexpected processes of self-organization, such as condensation, or incoherent soliton generation in instantaneous response nonlinear media. Such self-organization processes may be characterized by a reduction of the non-equilibrium entropy, which violates the Boltzmann's H-theorem of entropy growth inherent to the wave turbulence theory.

The interaction of spatial optical solitons in nematic liquid crystals or nematiconswith electrically induced waveguides is investigated experimentally and numerically. Our observations show that broad multimode waveguides are able to guide nematiconsand permit an angular steering of the signal. This opens the way to combining the all-optical properties of spatial solitons with the reconfigurability of the electrically induced waveguides. Our numerical model is in good agreement with the observed phenomena.

With the variational method we analytically study rotating vector soliton bound states in Kerr media. A standard linear stability analysis reveals that, in the presence of nonlinear birefringence, these soliton bound states exhibit a symmetry-breaking instability. In the absence of nonlinear birefringence, that is, in the Manakov system, the bound states are shown to be neutrally stable and not robust against soliton collisions. We show that these stability properties are not influenced by saturation of the nonlinearity, a result that is relevant to recent experimental observations of soliton bound states in photorefractive media.

We study the role of polarization in modulational instabilities in a synchronously pumped ring resonator that is filled with an isotropic nonlinear dispersive medium. To describe nonlinear propagation of the polarized field through the ring, we introduce two coupled driven and damped nonlinear Schrödinger equations. These equations, which result from averaging propagation and boundary conditions over each circulation through the ring, permit a simple stability analysis. This analysis predicts polarization multistability in the steady state as well as the emergence of stable pulse trains whose polarization state is either parallel or orthogonal to a linearly polarized synchronous pump beam. The analytical predictions are confirmed and extended by numerical simulations of polarized wave propagation in the cavity.

We investigate theoretically and experimentally the nonlinear dynamics of a synchronously pumped all-fiber passive ring cavity. Our study is based on the use of a specially designed stabilization system that allows for interferometric control of the cavity length. With this system we can achieve stable operation and we are able to perform systematic and reproducible measurements for the characterization of the fundamental nonlinear behaviors of the cavity such as optical bistability, period doubling instabilities, and dissipative modulational instabilities. Through the analysis of the output pulse spectra we show that modulational instability plays a crucial role in the dynamics of the cavity (in particular, in the period-doubling route to chaos) even with normal group-velocity dispersion. A theoretical study of modulational instability in the cavity is presented and is successfully compared with experimental results.

Four-photon mixing in a low-birefringence fiber is strongly influenced by the orientation of the pump and signal waves with respect to the fiber axes. We experimentally investigated the dependence of the modulational gain spectra on pump power and polarization by mixing orthogonal pump and probe light beams in a birefringent optical fiber. With a pump on the fast fiber axis, a cascade of sidebands was generated in the regime of normal fiber dispersion. These sidebands are shown to correspond to 0.2–0.3-THz trains of pulses with complex polarization profiles. The analysis reveals that, at particular values of the input pump and probe powers and signal frequency detuning, trains of dark-solitonlike pulses can be generated on the axis orthogonal to the pump.

The role of transverse effects in the polarization dynamics of light beams propagating in Kerr materials is investigated. We show the existence of a novel class of vector-dark solitary waves in these materials in both two- and three-dimensional geometries. These solitary waves consist of localized structures separating domains of different polarization eigenstates of the Kerr medium. The stability of these new nonlinear waves and the dynamics of related structures is investigated by numerical simulations.

A unified nonlinear modal theory that is valid not only for waveguide couplers but also for nonlinear Fabry–Perot resonators has recently been proposed. The validity of this new approach is numerically demonstrated by comparison with the well-known bidimensional theory. The unified modal theory appears to be a powerful tool for studying transverse effects in a broad class of nonlinear resonators. It has been used to derive the main characteristics of the stationary behavior of the optical resonators in the case of a local nonlinearity. In particular, the disappearance of optical bistability when the resonator is tilted is predicted. Optical bistability at nearly normal incidence is interpreted by the coupling between two resonantly excited counterpropagating modes that are at the origin of the required transverse feedback.

On the basis of a pole analysis, we derive a simple and powerful model of the nonlinear Fabry–Perot resonator. Our theory extends the modal approach, which was already developed for the nonlinear prism coupler, to the Fabry–Perot resonator for any angle of incidence. The main advantage of the modal approach is that it greatly simplifies the numerical study of transverse effects and provides a deep understanding of physical phenomena related to optical bistability. By means of a simple analysis of the equations, our model permits us to discuss the role of diffraction and the influence of the incident angle on the nonlinear Fabry–Perot behavior.

By means of a simplified model we study the dynamics of transverse effects in the nonlinear Fabry–Perot resonator illuminated under both normal and oblique incidences. We show that oblique incidence leads to a new kind of instability characterized by the onset of periodic self-pulsing. On the basis of a simple linear stability analysis, we interpret this instability in terms of a drift of spatial dissipative structures.

We report the experimental shaping of dark-soliton pulse trains at a several-gigahertz repetition rate by means of a simple sinusoidal fiber Bragg grating used as a highly resolving passive filtering element at the output of a conventional mode-locked laser source. We show that the proper choice of grating parameters allows for the transformation of bright-pulse trains into odd-symmetry dark-pulse trains with cw background. The results of a propagation experiment with a 7-km-long fiber demonstrate, together with numerical simulations, the efficiency of the new shaping method.

The transverse snake instability of the bright soliton solution of the (2+1)-dimensional hyperbolic nonlinear Schrödinger equation is experimentally studied. We observed this instability in the spatial ditribution of the temporal spectrum of spatially extended femtosecond pulses propagating in normally dispersive self-defocusing planar semiconductor waveguide.

We report a detailed experimental study of vector modulation instability in highly birefringent optical fibers in the anomalous-dispersion regime. We prove that the observed instability is mainly induced by vacuum fluctuations. The detuning of the spectral peaks agrees with linear perturbation analysis. The exact shape of the spectrum is well reproduced by numerical integration of stochastic nonlinear Schrödinger equations describing quantum propagation.

By means of a dynamic Bragg grating obtained through cross-phase modulation with a beating wave in a highly birefringent fiber, we perform a detailed experimental study of Bragg modulational instability.

On the basis of simple physical arguments involving energy flows and power invariants, we show that nonparaxiality stabilizes 1+2D soliton beams in Kerr media.

The theory of the Gordon–Haus effect with application to dark solitons is presented. It is proved analytically that a random frequency shift of a fundamental dark soliton results in a time jitter 2 times lower than that for bright solitons.

Theory and experiments show that the nonlinear development of the modulational polarization instability of an intense light beam in a normally dispersive, low-birefringence optical fiber leads to ultrashort dark-soliton-like trains with repetition rates in the terahertz range in the polarization orthogonal to the pump.

We present a study of the dynamics of multiple soliton bound states in diffractive media with second-order nonlinearity. A numerical stability analysis of these bound states reveals that wave propagation in quadratic materials exhibits spatial symmetry-breaking instabilities.

We show, taking dispersion into account, that second-harmonic generation in a cavity can be modulationally unstable. In the monostable mode of operation this instability might predominate with respect to self-pulsing instabilities, leading to the generation of stable solitarylike pulse trains.

We present a new class of dark circularly symmetric solitary wave in bulk, self-defocusing Kerr media. The waves comprise two orthogonally polarized fields mutually guiding each other and forming separate polarization domains. The stability of these new solutions and the dynamics of related structures are briefly investigated.

The theory of the Gordon-Haus effect with application to dark solitons is presented. It is proved analytically that a random frequency shift of a fundamental dark soliton results in a time jitter √2 times lower than that for bright solitons.

On the basis of a simple analysis of the coupled nonlinear Schrödinger equations that govern pulse propagation in isotropic nonlinear dispersive media, we show the existence of a novel class of bound-vector solitary waves. These solitary waves are novel in exhibiting elliptical polarization that varies across the pulse and evolves periodically during propagation while the pulse intensity envelope remains unchanged. Simple physical arguments allow us to understand the existence and the features of these particular solutions.

We demonstrate experimentally the existence of cross-phase-modulation-induced modulational instability in the absence of group-velocity mismatch between the interacting nonlinear dispersive waves. The experiment is performed by means of a normally dispersive isotropic bimodal fiber. The group-velocity mismatch between the fundamental and the first-order modes that constitute the two interacting waves is controlled by wavelength tuning. A strong power dependence of the modulational instability spectra is observed near the condition of group-velocity matching.

We investigate modulational instability in normally dispersive highly birefringent fibers. By means of a technique based on a two-frequency pump field we are able to provide evidence for strong nonlinear dependence of the modulational instability spectra. This dependence manifests itself by the appearance of a nonlinear spectral gap in which modulational instability vanishes.

A new type of optical solitary wave is shown to exist in W-type single-mode fibers. These solitary waves consist of localized structures separating two uniform fields of different frequencies. Their application to optical communications is considered. We show that their topology is adapted to the nonreturn-to-zero modulation format and that their fundamental features offer important advantages with respect to the usual soliton transmission scheme.

A novel type of vector dark solitary wave is shown to exist in Kerr materials. These solitary waves consist of localized structures separating adjacent regions (or domains) of different polarization eigenstates of the Kerr medium.

We report the observation of nonlinear propagation of picosecond odd-symmetry dark pulses over 1-km single-mode fiber in the near infrared. The pulses are shown to propagate without distortion at the power corresponding to the fundamental dark soliton of the nonlinear Schrödinger equation. Our measurements are in quantitative agreement with numerical solutions to a modified nonlinear Schrödinger equation—including fiber loss—and constitute the first evidence to our knowledge of dark soliton propagation over fiber lengths compatible with optical telecommunication systems.

A new theoretical approach for the study of the influence of diffraction on Ikeda instability in the Kerr-type nonlinear ring cavity is proposed. The simplicity of this model allows for a complete analytical study of transverse modulational instability in the period-2 regime of the cavity. In particular the emergence of stationary spatial dissipative structures in the profile of the period-doubled transmitted beam is predicted.

A synchronously pumped modulational-instability ring laser with a nonlinear dispersive fiber can be operated in both the anomalous and the normal dispersion regimes. We obtain simple analytical expressions for the sideband gain in the cavity by using an average pulse formalism. The numerical simulations indicate that stable stationary trains of pulses may be formed in the cavity. This is independent of the sign of the dispersion.

The transmission of dark solitons in ultralong transmission systems with optical amplification is numerically investigated. We show that amplifier noise is responsible for a random frequency shift with a resulting time jitter 2 times lower than that observed for bright solitons.

A recent modal theory of nonlinear planar resonators is applied to the analysis of the steady transmission characteristics of the two-beam nonlinear Fabry–Perot interferometer. An analytical study, based on the plane-wave approximation, is presented that shows the potential applications of the device. In particular, a flip-flop mode of operation, derived from a pitchfork bifurcation, is predicted. Its salient feature is to require only positive triggering pulses.

The Letter reveals the bandwidth limits that result from the interactions between orthogonally polarised solitons in an optical fibre transmission link with time and polarisation division multiplexing.

A method for the generation of soliton trains at ultrahigh repetition rates is proposed. The method is based on the dual-frequency pumping of a passive fibre ring cavity. At the output port of the cavity, a train of independent pulses with hyperbolic secant profile is emitted.

We describe the bistable behavior of a nonlinear triple-boundary slab waveguide. We show that, in addition to the previously reported reflected intensity bistability, this device exhibits bistability in the phase of the reflected beam. It is shown that pure phase signal bistability is possible. A system based on the Mach–Zehnder interferometric configuration is proposed to achieve a high-contrast bistable switch.

Nous étudions la dynamique non linéaire des états de polarisation de deux ondes cohérentes ou incohérentes se propageant dans une fibre optique. Nous présentons en particulier un effet original d'attraction de la polarisation.

Experimental observation of passive modelocking by dissipative four-wave mixing in an erbium-doped fibre laser containing a dual-peak fibre Bragg-grating filter is reported. The laser operates in the normal dispersion regime and generates optical dark pulse trains with a repetition rate of 80 GHz.

It is shown that interaction forces between two solitons in a circular fibre can be cancelled exactly by means of a reshaping of their envelope and a proper choice of their polarisation and relative phase. The resulting soliton bound state exhibits polarisation rotation at a rate that depends on the initial pulse separation.

Nonlinear polarisation switching of picosecond pulses from the linear polarisation eigenstates of a 200 m-long low-birefringence spun fibre is reported. The relatively low switching peak power of 20 W is promising for applications to all-optical processing and intensity discrimination of ultra-short pulses.

A new type of optical solitary wave is shown to exist in dispersion-flattened singlemode fibres. These solitary waves consist of localised structures separating two uniform fields of different frequencies. Their applications to optical transmission systems are briefly discussed.