The noise properties of non-degenerate parametric amplifiers with absorption losses which are dif... more The noise properties of non-degenerate parametric amplifiers with absorption losses which are different for the two beams are analysed by means of a semiclassical approach which enables the direct derivation of the Langevin equations for the optical fields from the quantum Heisenberg equations. Several statistical quantities are calculated and the implications of the present results for sub shot-noise absorption measurements are discussed finally.
In this contribution we describe recent results on the generation and control of temporal localiz... more In this contribution we describe recent results on the generation and control of temporal localized structures in a passively mode-locked Vertical-Cavity Surface-Emitting Laser mounted in an external cavity closed by a resonant saturable absorber mirror. When the cavity roundtrip is much larger than the medium timescales, this system exhibits a temporal aspect-ratio large enough to host pulses which can be individually addressed. These localized pulses have been proposed as information bits and the possibility of their manipulation opens interesting perspectives for information processing. We will show that a modulation of the pumping current leads to control the position and the speed of the localized pulses within the cavity. In addition to pin the pulses at well-defined positions, which enables clocking the bit flow, the pulses can be driven to collide one against the other, thus unveiling the purely repulsive mutual interaction.
2003 European Quantum Electronics Conference. EQEC 2003 (IEEE Cat No.03TH8665)
ABSTRACT This work performs numerical and experimental studies of coupled mode dynamics for monol... more ABSTRACT This work performs numerical and experimental studies of coupled mode dynamics for monolithic semiconductor ring lasers. This study presents numerical analysis and experimental results of the different operating regimes, namely: bidirectional CW, bidirectional with harmonic oscillations of the mode intensities, and unidirectional.
We have developed a comprehensive theoretical description of passive mode-locked semiconductor la... more We have developed a comprehensive theoretical description of passive mode-locked semiconductor lasers based on a coarse-grained time-domain approach. The results are compared with the performance of a passively mode-locked AlGaInAs strained quantum well lasers.
2011 Numerical Simulation of Optoelectronic Devices, 2011
We present a general method allowing to perform a direct bifurcation diagram and to determine the... more We present a general method allowing to perform a direct bifurcation diagram and to determine the stability of the solutions of a Traveling wave model. We exemplify the cases of the two level atom and the semiconductor quantum well lasers. I. INTRODUCTION The Maxwell-Bloch equations governing the laser dynamics can be regarded as a singularly perturbed problem: the fast re-
Transverse-mode competition and polarization selection in gain-guided vertical-cavity surface-emi... more Transverse-mode competition and polarization selection in gain-guided vertical-cavity surface-emitting lasers are studied by use of a transverse continuous model that incorporates basic physical mechanisms of polarization dynamics. Polarization stability and polarization switching within the fundamental Gaussian mode are described. The first-order transverse mode always starts lasing orthogonally polarized to the fundamental one. At larger currents polarization coexists with several active transverse modes. These results are shown to be sensitive to the carrier spin-flip relaxation rate.
Journal of Optics B: Quantum and Semiclassical Optics, 2000
... In a VCSEL one also has to be aware of the possibility of polarization dynamics (eg [1721]).... more ... In a VCSEL one also has to be aware of the possibility of polarization dynamics (eg [1721]). The spectra show ... also found. A detailed study of the polarization properties of these broad-area devices remains to be done. Finally ...
In this work we analyze the ground state of CeOsxRu2-x from a self-energy functional deduced with... more In this work we analyze the ground state of CeOsxRu2-x from a self-energy functional deduced within the GW approximation for a multiband Anderson-Hubbard hamiltonian. The resulting DOS and fDOS are related to the superconducting properties of these compounds within the Anderson-Brinkmann theory.
ABSTRACT The random phase approximation integral equation is solved for obtaining the dynamically... more ABSTRACT The random phase approximation integral equation is solved for obtaining the dynamically screened interaction between d electrons (Wd(ω)), p electrons (Wp(ω)) and p/d electrons (Wpd(ω)). Some characteristic divergence of this last interaction correspond to the plasmon frequencies which one can relate with the effective masses of the p and d electrons close to EF by means of the relation ωp1/ωp2 = (m2/m1)1/2. ZAnother feature of this Wpd(ω) interaction is the attractive character for low frequencies. The lowest frequency for which ɛpd = 0 decreases when the localization of states close to EF arising from the χ2-y2 symmetry increases.
The noise properties of non-degenerate parametric amplifiers with absorption losses which are dif... more The noise properties of non-degenerate parametric amplifiers with absorption losses which are different for the two beams are analysed by means of a semiclassical approach which enables the direct derivation of the Langevin equations for the optical fields from the quantum Heisenberg equations. Several statistical quantities are calculated and the implications of the present results for sub shot-noise absorption measurements are discussed finally.
In this contribution we describe recent results on the generation and control of temporal localiz... more In this contribution we describe recent results on the generation and control of temporal localized structures in a passively mode-locked Vertical-Cavity Surface-Emitting Laser mounted in an external cavity closed by a resonant saturable absorber mirror. When the cavity roundtrip is much larger than the medium timescales, this system exhibits a temporal aspect-ratio large enough to host pulses which can be individually addressed. These localized pulses have been proposed as information bits and the possibility of their manipulation opens interesting perspectives for information processing. We will show that a modulation of the pumping current leads to control the position and the speed of the localized pulses within the cavity. In addition to pin the pulses at well-defined positions, which enables clocking the bit flow, the pulses can be driven to collide one against the other, thus unveiling the purely repulsive mutual interaction.
2003 European Quantum Electronics Conference. EQEC 2003 (IEEE Cat No.03TH8665)
ABSTRACT This work performs numerical and experimental studies of coupled mode dynamics for monol... more ABSTRACT This work performs numerical and experimental studies of coupled mode dynamics for monolithic semiconductor ring lasers. This study presents numerical analysis and experimental results of the different operating regimes, namely: bidirectional CW, bidirectional with harmonic oscillations of the mode intensities, and unidirectional.
We have developed a comprehensive theoretical description of passive mode-locked semiconductor la... more We have developed a comprehensive theoretical description of passive mode-locked semiconductor lasers based on a coarse-grained time-domain approach. The results are compared with the performance of a passively mode-locked AlGaInAs strained quantum well lasers.
2011 Numerical Simulation of Optoelectronic Devices, 2011
We present a general method allowing to perform a direct bifurcation diagram and to determine the... more We present a general method allowing to perform a direct bifurcation diagram and to determine the stability of the solutions of a Traveling wave model. We exemplify the cases of the two level atom and the semiconductor quantum well lasers. I. INTRODUCTION The Maxwell-Bloch equations governing the laser dynamics can be regarded as a singularly perturbed problem: the fast re-
Transverse-mode competition and polarization selection in gain-guided vertical-cavity surface-emi... more Transverse-mode competition and polarization selection in gain-guided vertical-cavity surface-emitting lasers are studied by use of a transverse continuous model that incorporates basic physical mechanisms of polarization dynamics. Polarization stability and polarization switching within the fundamental Gaussian mode are described. The first-order transverse mode always starts lasing orthogonally polarized to the fundamental one. At larger currents polarization coexists with several active transverse modes. These results are shown to be sensitive to the carrier spin-flip relaxation rate.
Journal of Optics B: Quantum and Semiclassical Optics, 2000
... In a VCSEL one also has to be aware of the possibility of polarization dynamics (eg [1721]).... more ... In a VCSEL one also has to be aware of the possibility of polarization dynamics (eg [1721]). The spectra show ... also found. A detailed study of the polarization properties of these broad-area devices remains to be done. Finally ...
In this work we analyze the ground state of CeOsxRu2-x from a self-energy functional deduced with... more In this work we analyze the ground state of CeOsxRu2-x from a self-energy functional deduced within the GW approximation for a multiband Anderson-Hubbard hamiltonian. The resulting DOS and fDOS are related to the superconducting properties of these compounds within the Anderson-Brinkmann theory.
ABSTRACT The random phase approximation integral equation is solved for obtaining the dynamically... more ABSTRACT The random phase approximation integral equation is solved for obtaining the dynamically screened interaction between d electrons (Wd(ω)), p electrons (Wp(ω)) and p/d electrons (Wpd(ω)). Some characteristic divergence of this last interaction correspond to the plasmon frequencies which one can relate with the effective masses of the p and d electrons close to EF by means of the relation ωp1/ωp2 = (m2/m1)1/2. ZAnother feature of this Wpd(ω) interaction is the attractive character for low frequencies. The lowest frequency for which ɛpd = 0 decreases when the localization of states close to EF arising from the χ2-y2 symmetry increases.
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Papers by Salvador Balle