H. Michinel - Academia.edu (original) (raw)

Papers by H. Michinel

Physical Review Letters, 2014

We study the cubic (focusing)-quintic (defocusing) non-linear Schrödinger equation in two transve... more We study the cubic (focusing)-quintic (defocusing) non-linear Schrödinger equation in two transverse dimensions. We discuss a family of stationary travelling waves, including rarefaction pulses and vortex-antivortex pairs, in a background of critical amplitude. We show that these rarefaction pulses can be generated inside a top-flat soliton when a smaller bright soliton collides with it. The fate of the evolution strongly depends on the relative phase of the solitons. Among several possibilities, we find that the dark pulse can re-emerge as a bright soliton.

Physical Review Letters, 2009

We show that a laser beam which propagates through an optical medium with Kerr (focusing) and hig... more We show that a laser beam which propagates through an optical medium with Kerr (focusing) and higher order (defocusing) nonlinearities displays pressure and surface-tension properties yielding capillarity and dripping effects totally analogous to usual liquid droplets. The system is reinterpreted in terms of a thermodynamic grand potential, allowing for the computation of the pressure and surface tension beyond the usual hydrodynamical approach based on Madelung transformation and the analogy with the Euler equation. We then show both analytically and numerically that the stationary soliton states of such a light system satisfy the Young-Laplace equation and that the dynamical evolution through a capillary is described by the same law that governs the growth of droplets in an ordinary liquid system.

Physical Review A, 2009

The propagation of probe and coupling optical beams through a four-level coherent media is modele... more The propagation of probe and coupling optical beams through a four-level coherent media is modeled by two coupled nonlinear Schrödinger equations. The nonlinear susceptibilities exhibited by the four-level media are calculated in the nonperturbative regime, i.e., considering the probe and coupling fields as having comparable amplitudes. We address the existence and stability of vector solitons build by the probe and coupling beams in the coupled nonlinear Schrödinger equations.

$Research paper thumbnail of Light by light diffraction in vacuum$

Physical Review A, 2010

We show that a laser beam can be diffracted by a more concentrated light pulse due to quantum vac... more We show that a laser beam can be diffracted by a more concentrated light pulse due to quantum vacuum effects. We compute analytically the intensity pattern in a realistic experimental configuration, and discuss how it can be used to measure for the first time the parameters describing photon-photon scattering in vacuum. In particular, we show that the Quantum Electrodynamics prediction can be detected in a single-shot experiment at future 100 petawatt lasers such as ELI or HIPER. On the other hand, if carried out at one of the present high power facilities, such as OMEGA EP, this proposal can lead either to the discovery of non-standard physics, or to substantially improve the current PVLAS limits on the photon-photon cross section at optical wavelengths. This new example of manipulation of light by light is simpler to realize and more sensitive than existing, alternative proposals, and can also be used to test Born-Infeld theory or to search for axion-like or minicharged particles.

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences

In recent years, many different in-orbit close-range autonomous operations have been developed fo... more In recent years, many different in-orbit close-range autonomous operations have been developed for multiple purposes, such as rendezvous and docking operations or ADR operations. In both cases, the systems have to calculate the relative position between the spacecraft and the target in order to control the orbital manoeuvres and the physic interaction between both systems. One of the sensors used for the pose calculation for these operations are LiDAR sensors, developing pose calculation algorithms that process the point cloud acquired by these sensors. One of the main problems for the development and testing of these algorithms is the lack of real data acquired in orbit and the difficulty of acquiring this data. This makes it fundamental to develop a simulator to generate realistic point clouds that can be used to develop and test pose calculation algorithms. This work presents a simulator developed for this purpose, that is the generation of realistic point clouds for algorithm development for pose calculation using LiDAR sensors for space in-orbit close range autonomous operations. The simulator uses the LiDAR sensor specifications, in order to introduces measurement errors and the scanning pattern, and 3D model of the satellite or object that is scanned.

2011 11th International Conference on Laser and Fiber-Optical Networks Modeling (LFNM), 2011

ABSTRACT Atomic soliton lasers are coherent matter-wave emitters that produce localized pulses of... more ABSTRACT Atomic soliton lasers are coherent matter-wave emitters that produce localized pulses of atoms that are extracted from an ultracold atomic reservoir. In adequate conditions it is possible to obtain matter-wave soliton trains that propagate undistorted, a property that makes them very useful for ultra-sensitive measurements like gravity-waves detection or atomic interferometry. Some new applications and results will we presented.

We present a numerical analysis and experimental measurements of the temperature stabilization of... more We present a numerical analysis and experimental measurements of the temperature stabilization of high-power LED chips that we have obtained by employing an aluminium passive heat sink, designed to be used in a compact light bulb configuration. We demonstrate that our system keeps the temperature of the LED chip well-below 60°C yielding long-term operation of the device. Our simulations have been performed for a device of low fabrication costs and which enables an easy installation in public streetlights. The experimental measurements performed in different configurations show a nice agreement with the numerical calculations.

Optical and Quantum Electronics, 1998

ABSTRACT Pulsed beam propagation at nonlinear ion-exchange waveguides has been analysed. Critical... more ABSTRACT Pulsed beam propagation at nonlinear ion-exchange waveguides has been analysed. Critical values of input power and film thickness to obtain emission and excitation of nonlinear surface pulses have been calculated by means of a variational approach in the dispersionless approximation. The analytical expressions obtained can be used as a qualitative guide for deeper computational exploration of the propagation problem and show a good agreement with the numerical simulations presented.

Physical Review E, 2014

We consider a system of two cubic-quintic non-linear Schrödinger equations in two dimensions, cou... more We consider a system of two cubic-quintic non-linear Schrödinger equations in two dimensions, coupled by repulsive cubic terms. We analyse situations in which a probe lump of one of the modes is surrounded by a fluid of the other one and analyse their interaction. We find a realization of D'Alembert's paradox for small velocities and non-trivial drag forces for larger ones. We present numerical analysis including the search of static and traveling form-preserving solutions along with simulations of the dynamical evolution in some representative examples.

Physical Review A, 2008

In a recent paper, we have shown that the QED nonlinear corrections imply a phase correction to t... more In a recent paper, we have shown that the QED nonlinear corrections imply a phase correction to the linear evolution of crossing electromagnetic waves in vacuum. Here, we provide a more complete analysis, including a full numerical solution of the QED nonlinear wave equations for short-distance propagation in a symmetric configuration. The excellent agreement of such a solution with the result that we obtain using our perturbatively-motivated Variational Approach is then used to justify an analytical approximation that can be applied in a more general case. This allows us to find the most promising configuration for the search of photon-photon scattering in optics experiments. In particular, we show that our previous requirement of phase coherence between the two crossing beams can be released. We then propose a very simple experiment that can be performed at future exawatt laser facilities, such as ELI, by bombarding a low power laser beam with the exawatt bump.

Optical and Quantum Electronics, 1996

ABSTRACT Secondary bistable solitons have been calculated for a non-linear optical inhomogeneous ... more ABSTRACT Secondary bistable solitons have been calculated for a non-linear optical inhomogeneous medium with parabolic gradient index and quadratic intensity-dependent refractive index change. The remarkable effect of inhomogeneities on the existence and stability of bistable solitons has been studied. The results obtained are compared with those from homogeneous solitons.

Pure and Applied Optics: Journal of the European Optical Society Part A, 1995

Gaussian beam propagation in planar GRIN waveguides with non-linear refractive index has been stu... more Gaussian beam propagation in planar GRIN waveguides with non-linear refractive index has been studied by means of the well known Anderson variational method, improved with a more general trial function. Analytical expressions for oscillations of both the beam waist and the centre of the beam have been derived. The solutions obtained yield a very simple picture of the behaviour of Gaussian light beams in this kind of media and are in excellent agreement with the numerical calculations presented.

Pure and Applied Optics: Journal of the European Optical Society Part A, 1997

ABSTRACT The propagation of pulsed Gaussian beams end-firing the fundamental mode of a linear thi... more ABSTRACT The propagation of pulsed Gaussian beams end-firing the fundamental mode of a linear thin film covered with a nonlinear medium has been analysed by means of a variational method. Fundamental parameters for soliton emission and nonlinear surface wave propagation, such as critical power and film thickness, have been calculated. The role of the pulse shape has been investigated by comparing the behaviour of Gaussian and hyper-Gaussian pulses. The variational expressions obtained for the evolution of the beam width and trajectory are shown to be in good agreement with numerical simulations.

Pure and Applied Optics: Journal of the European Optical Society Part A, 1994

ABSTRACT For a non-linear optical fibre with quadratic intensity-dependent refractive index chang... more ABSTRACT For a non-linear optical fibre with quadratic intensity-dependent refractive index change, bistable solitons have been calculated. Bistability has been considered as the existence of two different amplitude shapes for the same soliton temporal width. It is demonstrated that boundary conditions (finite radius of the fibre) have a remarkable effect on the existence of bistable solitons. Results are compared with those obtained for the homogeneous case, where the effect of boundaries was not considered.

Conference Digest. 2000 Conference on Lasers and Electro-Optics Europe (Cat. No.00TH8505), 2000

ABSTRACT Summary form only given. We analyse numerically, the propagation of a light condensate t... more ABSTRACT Summary form only given. We analyse numerically, the propagation of a light condensate through a bulk PTS-like nonlinear optical material in the presence of boundary conditions and localised inhomogeneities. The propagation equation for the above waveguide in the paraxial regime is a generalised nonlinear Schrodinger equation (NLSE), including cubic-quintic terms and the effect of boundaries or localised inhomogeneities