Broadening of mode-locking pulses in quantum-dot semiconductor lasers : simulation, analysis and experiments

We consider a mode-locked quantum-dot edge-emitting semiconductor laser consisting of a reverse biased saturable absorber and a forward biased amplifying section. To describe the dynamics of this laser we use the traveling wave model taking into account carrier exchange processes between a reservoir and the quantum dots. A comprehensive parameter study is presented and an analysis of mode-locking pulse broadening with an increase of injection current is performed. The results of our theoretical analysis are supported by experimental data demonstrating a strong pulse asymmetry in a monolithic two section quantum dot mode-locked lase

Broadening of mode-locking pulses in quantum-dot semiconductor lasers: Simulation, analysis and experiments

We consider a mode-locked quantum-dot edge-emitting semiconductor laser consisting of a reverse biased saturable absorber and a forward biased amplifying section. To describe the dynamics of this laser we use the traveling wave model taking into account carrier exchange processes between a reservoir and the quantum dots. A comprehensive parameter study is presented and an analysis of mode-locking pulse broadening with an increase of injection current is performed. The results of our theoretical analysis are supported by experimental data demonstrating a strong pulse asymmetry in a monolithic two section quantum dot mode-locked laser

Strong asymmetry of mode-locking pulses in quantum-dot semiconductor lasers

We describe the formation of a strong pulse asymmetry in mode-locked quantum-dot edge-emitting two-section semiconductor lasers. A mode decomposition technique reveals the role of the superposition of different modal groups. The results of theoretical analysis are supported by experimental data

Strong asymmetry of mode-locking pulses in quantum-dot semiconductor lasers

We describe the formation of a strong pulse asymmetry in mode-locked quantum-dot edge-emitting two-section semiconductor lasers. A mode decomposition technique reveals the role of the superposition of different modal groups. The results of theoretical analysis are supported by experimental data

Segmented optical transmitter comprising a CMOS driver array and an InP IQ-MZM for advanced modulation formats

Segmented Mach-Zehnder modulators are promising solutions to generate complex modulation schemes in the migration towards optical links with a higher-spectral efficiency. We present an optical transmitter comprising a segmented-electrode InP IQ-MZM, capable of multilevel optical signal generation (5-bit per I/Q arm) by employing direct digital drive from integrated, low-power (1W) CMOS binary drivers. We discuss the advantages and design tradeoffs of the segmented driver structure and the implementation in a 40 nm CMOS technology. Multilevel operation with combined phase and amplitude modulation is demonstrated experimentally on a single MZM of the device for 2-ASK-2PSK and 4-ASK-2-PSK, showing potential for respectively 16-QAM and 64-QAM modulation in future assemblies

Dynamical regimes in a monolithic passively mode-locked quantum dot laser

Operation regimes of a two section monolithic quantum dot (QD) mode-locked laser are studied experimentally and theoretically, using a model that takes into account carrier exchange between QD ground state and 2D reservoir of a QD-in-a-well structure, and experimentally. It is shown analytically and numerically that, when the absorber section is long enough, the laser exhibits bistability between laser off state and different mode-locking regimes. The Q-switching instability leading to slow modulation of the mode-locked pulse peak intensity is completely eliminated in this case. When, on the contrary, the absorber length is rather short, in addition to usual Q-switched mode-locking, pure Q-switching regimes are predicted theoretically and observed experimentally

Dynamical regimes in a monolithic passively mode-locked quantum dot laser

Operation regimes of a two section monolithic quantum dot (QD) mode-locked laser are studied experimentally and theoretically, using a model that takes into account carrier exchange between QD ground state and 2D reservoir of a QD-in-a-well structure, and experimentally. It is shown analytically and numerically that, when the absorber section is long enough, the laser exhibits bistability between laser off state and different mode-locking regimes. The Q-switching instability leading to slow modulation of the mode-locked pulse peak intensity is completely eliminated in this case. When, on the contrary, the absorber length is rather short, in addition to usual Q-switched mode-locking, pure Q-switching regimes are predicted theoretically and observed experimentally

Strong pulse asymmetry in quantum-dot mode-locked semiconductor lasers

We describe the formation of a strong pulse asymmetry in mode-locked quantum-dot edge-emitting two-section semiconductor lasers. A mode decomposition technique reveals the role of the superposition of different modal groups. The results of theoretical analysis are supported by the experimental data. © 2011 American Institute of Physics.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Pulse Broadening in Quantum-Dot Mode-Locked Semiconductor Lasers: Simulation, Analysis, and Experiments

We consider a mode-locked (ML) quantum-dot (QD) edge-emitting semiconductor laser consisting of a reverse-biased saturable absorber and a forward-biased amplifying section. To describe the dynamics of this laser, we use the traveling wave model taking into account carrier exchange processes between a reservoir and the QDs. A comprehensive parameter study is presented and an analysis of mode-locking pulse broadening with an increase of injection current is performed. The results of our theoretical analysis are supported by experimental data demonstrating a strong pulse asymmetry in a monolithic two-section QD laser

Hybrid mode-locking in a 40 GHz monolithic quantum dot laser

This work studies experimentally and theoretically a monolithic two-section hybrid mode-locked quantum dot laser with periodically modulated reverse bias applied to the saturable absorber section. Experimental investigations have been carried out with a 40 GHz QD-MLL (quantum dot mode-locked lasers) module, comprising a standard single mode fiber pigtail and a microwave port. It is based on a two-section QD laser diode having a 4 mum wide ridge waveguide structure. A theoretical model of a quantum dot laser is based on a set of delay differential equations governing the time evolution of the electric field envelope, carrier densities in the wetting layers and occupation probabilities of the quantum dots in the gain absorber sections.SCOPUS: cp.pThe European Conference on Lasers and Electro-Optics, CLEO_Europe 2009; Munich; Germany; 14 June 2009 through 19 June 2009info:eu-repo/semantics/publishe