ABSTRACT The degradation of the side-mode suppression ratio (SMSR) in an integrated DFB laser and... more ABSTRACT The degradation of the side-mode suppression ratio (SMSR) in an integrated DFB laser and semiconductor optical amplifier (SOA) cavity is investigated. A numerical model combining finite element calculations in the x-y plane and a longitudinal model based on the Green's function approach is used for that purpose. An expression is derived that expresses the degradation of the SMSR in the case of a perfectly AR-coated SOA facet. It is shown that the ASE backcoupling can have dramatic effects and degrade and SMSR of single-mode devices to unacceptable levels.
ABSTRACT The problem of the linewidth degradation in systems using distributed-feedback lasers to... more ABSTRACT The problem of the linewidth degradation in systems using distributed-feedback lasers together with strained-layer multi-quantum-well semiconductor optical amplifiers (SOAs) is examined. A numerical model combining finite element calculations in the transverse x-y plane and a longitudinal model based on the Green's function method is used for that purpose. Simple expressions for the linewidth in the case of AR-coated SOA output facets are derived and simulation results are given in the case of an output facet with a non-vanishing reflectivity. It is found that optimal conditions for a narrow linewidth can be determined.
The electron capture time in single quantum wells is calculated by considering capture and escape... more The electron capture time in single quantum wells is calculated by considering capture and escape as scattering events in Monte Carlo simulation. The calculation is performed for an AlGaAs/GaAs quantum well as a function of the well width at 300 K. The overall capture time of carriers is found to be controlled by the transition from the free state to
1998 International Conference on Applications of Photonic Technology III: Closing the Gap between Theory, Development, and Applications, 1998
ABSTRACT We investigate vertical carrier transport, carrier relaxation and capture in three In1-x... more ABSTRACT We investigate vertical carrier transport, carrier relaxation and capture in three In1-xGaxAsyP1-y multiple-quantum-well lasers structures emitting at 1.3 and 1.55 micrometers at room temperature using time resolved photoluminescence. In the initial regime following the excitation, high effective carrier temperatures Tc different from the lattice temperature TL equals 77 K are reported. A significant signature of transport and capture is observed with characteristic times of approximately 10 ps and approximately 12 ps respectively.
Summaries of papers presented at the Conference on Lasers and Electro-Optics, 1996
Summary form only given. Single-mode DFB semiconductor lasers with wide modulation bandwidth and ... more Summary form only given. Single-mode DFB semiconductor lasers with wide modulation bandwidth and low frequency chirp are highly desirable for high-speed and long-haul optical telecommunication systems. The recently proposed push-pull DFB lasers have displayed many promising features for progress in that direction. Numerical work alone can not give sufficient insight in device operation. Using the spatially-dependent multimode rate equations for the modal field amplitudes we study for the first time analytically the AM and FM response and resonance frequency lasers. The formalism includes essential features such as longitudinal spatial hole burning, nonlinear gain compression, and sidemode contribution rigorously.
With the rapid increase in demand for voice, data, and video services, consideration is being giv... more With the rapid increase in demand for voice, data, and video services, consideration is being given to their transmission to the subscriber over optical fibers. Since video is the most demanding service from a transmission point of view, much consideration is given to modulation formats suitable for multichannel video transmission over optical fibers.
1997 Digest of the IEEE/LEOS Summer Topical Meeting: Vertical-Cavity Lasers/Technologies for a Global Information Infrastructure/WDM Components Technology/Advanced Semiconductor Lasers and Applications/Gallium Nitride Materials, Processing, and Devices (C, 2000
Gain-coupled DFB lasers have a complicated modal interaction influenced by the effects of spatial... more Gain-coupled DFB lasers have a complicated modal interaction influenced by the effects of spatial hole burning (SHB) and nonlinear gain compression (NGC) because of the carrier dependent longitudinally distributed structures. In order to obtain a better understanding of the high single mode performance of gain-coupled DFB lasers, we perform a self-consistent multimode analysis using spatially dependent rate equations for the carrier density N and the modal photon number in a steady state
Lasers and Electro-Optics Society, IEEE LEOS Annual Meeting, 1997
In this paper, we analyze the effects of non-homogeneous carrier distributions in both the transv... more In this paper, we analyze the effects of non-homogeneous carrier distributions in both the transverse and the longitudinal directions of multiple-quantum-well (MQW) distributed feedback (DFB) lasers. The analysis relies on both a very precise bi-dimensional (2D) finite-difference analysis on the quantum-well scale and on a transfer matrix analysis of the whole DFB laser cavity above threshold, that is in presence
Receiver sensitivity degradation caused by Rayleigh backscattering and coupler reflections is inv... more Receiver sensitivity degradation caused by Rayleigh backscattering and coupler reflections is investigated for bidirectional digital transmission systems. Experimental values for APD receiver sensitivity degradation in a system operating at a bit rate of 10 Mbits/s and at a wavelength of 830 nm were found to be within 2 to 3 dB (optical) of the values predicted by a simple theoretical
ABSTRACT The degradation of the side-mode suppression ratio (SMSR) in an integrated DFB laser and... more ABSTRACT The degradation of the side-mode suppression ratio (SMSR) in an integrated DFB laser and semiconductor optical amplifier (SOA) cavity is investigated. A numerical model combining finite element calculations in the x-y plane and a longitudinal model based on the Green's function approach is used for that purpose. An expression is derived that expresses the degradation of the SMSR in the case of a perfectly AR-coated SOA facet. It is shown that the ASE backcoupling can have dramatic effects and degrade and SMSR of single-mode devices to unacceptable levels.
ABSTRACT The problem of the linewidth degradation in systems using distributed-feedback lasers to... more ABSTRACT The problem of the linewidth degradation in systems using distributed-feedback lasers together with strained-layer multi-quantum-well semiconductor optical amplifiers (SOAs) is examined. A numerical model combining finite element calculations in the transverse x-y plane and a longitudinal model based on the Green's function method is used for that purpose. Simple expressions for the linewidth in the case of AR-coated SOA output facets are derived and simulation results are given in the case of an output facet with a non-vanishing reflectivity. It is found that optimal conditions for a narrow linewidth can be determined.
The electron capture time in single quantum wells is calculated by considering capture and escape... more The electron capture time in single quantum wells is calculated by considering capture and escape as scattering events in Monte Carlo simulation. The calculation is performed for an AlGaAs/GaAs quantum well as a function of the well width at 300 K. The overall capture time of carriers is found to be controlled by the transition from the free state to
1998 International Conference on Applications of Photonic Technology III: Closing the Gap between Theory, Development, and Applications, 1998
ABSTRACT We investigate vertical carrier transport, carrier relaxation and capture in three In1-x... more ABSTRACT We investigate vertical carrier transport, carrier relaxation and capture in three In1-xGaxAsyP1-y multiple-quantum-well lasers structures emitting at 1.3 and 1.55 micrometers at room temperature using time resolved photoluminescence. In the initial regime following the excitation, high effective carrier temperatures Tc different from the lattice temperature TL equals 77 K are reported. A significant signature of transport and capture is observed with characteristic times of approximately 10 ps and approximately 12 ps respectively.
Summaries of papers presented at the Conference on Lasers and Electro-Optics, 1996
Summary form only given. Single-mode DFB semiconductor lasers with wide modulation bandwidth and ... more Summary form only given. Single-mode DFB semiconductor lasers with wide modulation bandwidth and low frequency chirp are highly desirable for high-speed and long-haul optical telecommunication systems. The recently proposed push-pull DFB lasers have displayed many promising features for progress in that direction. Numerical work alone can not give sufficient insight in device operation. Using the spatially-dependent multimode rate equations for the modal field amplitudes we study for the first time analytically the AM and FM response and resonance frequency lasers. The formalism includes essential features such as longitudinal spatial hole burning, nonlinear gain compression, and sidemode contribution rigorously.
With the rapid increase in demand for voice, data, and video services, consideration is being giv... more With the rapid increase in demand for voice, data, and video services, consideration is being given to their transmission to the subscriber over optical fibers. Since video is the most demanding service from a transmission point of view, much consideration is given to modulation formats suitable for multichannel video transmission over optical fibers.
1997 Digest of the IEEE/LEOS Summer Topical Meeting: Vertical-Cavity Lasers/Technologies for a Global Information Infrastructure/WDM Components Technology/Advanced Semiconductor Lasers and Applications/Gallium Nitride Materials, Processing, and Devices (C, 2000
Gain-coupled DFB lasers have a complicated modal interaction influenced by the effects of spatial... more Gain-coupled DFB lasers have a complicated modal interaction influenced by the effects of spatial hole burning (SHB) and nonlinear gain compression (NGC) because of the carrier dependent longitudinally distributed structures. In order to obtain a better understanding of the high single mode performance of gain-coupled DFB lasers, we perform a self-consistent multimode analysis using spatially dependent rate equations for the carrier density N and the modal photon number in a steady state
Lasers and Electro-Optics Society, IEEE LEOS Annual Meeting, 1997
In this paper, we analyze the effects of non-homogeneous carrier distributions in both the transv... more In this paper, we analyze the effects of non-homogeneous carrier distributions in both the transverse and the longitudinal directions of multiple-quantum-well (MQW) distributed feedback (DFB) lasers. The analysis relies on both a very precise bi-dimensional (2D) finite-difference analysis on the quantum-well scale and on a transfer matrix analysis of the whole DFB laser cavity above threshold, that is in presence
Receiver sensitivity degradation caused by Rayleigh backscattering and coupler reflections is inv... more Receiver sensitivity degradation caused by Rayleigh backscattering and coupler reflections is investigated for bidirectional digital transmission systems. Experimental values for APD receiver sensitivity degradation in a system operating at a bit rate of 10 Mbits/s and at a wavelength of 830 nm were found to be within 2 to 3 dB (optical) of the values predicted by a simple theoretical
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Papers by R. Maciejko