40 GHz Mode-Locked Semiconductor Lasers: Theory, Simulations and Experiment

Bandelow, U.; Radziunas, Mindaugas; Vladimirov, Andrei; Hüttl, B.; Kaiser, R.

doi:10.1007/s11082-006-0045-2

Cited by 79 publications

(49 citation statements)

References 10 publications

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“…The region of Q-switching modulated ML, i.e., the region with strong side bands in the range of a few gigahertz, is small compared to that observed with quantum well lasers. 3 Both regions are separated by a steplike change of the SBSR by more than 30 dB. In our experiments, we did not observe any dependence of the SBSR plot on the scanning direction of the bias parameters.…”

contrasting

confidence: 38%

Stability of the mode-locked regime in quantum dot lasers

Viktorov

Mandel

Kuntz

et al. 2007

Applied Physics Letters

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We report on experimental and theoretical studies of the stability regime of passive mode-locked quantum dot lasers, which is decisively larger than in quantum well lasers. A small range of Q-switched instability is observed at low gain currents. Transition to Q switching is inhibited due to fast damping of the relaxation oscillations. A double pulse mode-locking regime appears for longer cavities, and exhibits bistability and coupling to the fundamental mode-locking operation. © 2007 American Institute of Physics. ͓DOI: 10.1063/1.2822808͔Passive and hybrid mode-locked ͑MLd͒ quantum dot lasers ͑QDLs͒ are efficient sources of short pulses ideal for applications in high speed communication systems. 1,2 The mode-locking ͑ML͒ regime of quantum well lasers can exhibit peak power fluctuations induced by a Q-switching instability, which is detrimental for the laser performance. In most experimental situations, QDLs have only a small range of Q switching instability, a consequence of the strong damping of the relaxation oscillations induced by the fast carrier capture from the wetting layer to the dots.In this letter, we study the stability of the mode-locked regime in QDLs with pulse repetition rates of 20 and 40 GHz. We find that stable ML in QDLs occurs in a comparatively larger range of parameters than in quantum well lasers. We also demonstrate the bifurcation to a state of doubled pulse repetition frequency in the MLd regime in longer cavity devices and characterize its coupling to the fundamental ML regime.The devices used in this work are two-section QDLs with a total length of 1 mm integrated in a module and an unpackaged 2 mm device ͑saturable absorber length is always 1 / 10 of the total length͒. The active region was grown on a GaAs substrate, containing 15 self-organized InAs QD layers. The facet near the absorber was high refection coated, the front facet was as cleaved. Details of the growth and the processing are the same as described in Ref. 2.A number of different regimes have been observed experimentally: Q-switching modulated ML, pure ML and, finally, cw lasing. The stability domains of these regimes are displayed in Fig. 1 for the 1 mm QDL module. We measured the radio frequency ͑rf͒ spectra of the optical output in the range of 0 -50 GHz by means of a 55 GHz bandwidth photodetector and a 50 GHz electrical spectrum analyzer. The side band suppression ratio ͑SBSR͒ with respect to the fundamental ML frequency at 40 GHz was extracted for a large set of reverse bias voltages and gain currents and plotted in Fig. 1. The large area of proper ML with a SBSR better than 20 dB, i.e., with weak or absent bands besides the fundamental ML frequency, dominates the figure. The region of Q-switching modulated ML, i.e., the region with strong side bands in the range of a few gigahertz, is small compared to that observed with quantum well lasers. 3 Both regions are separated by a steplike change of the SBSR by more than 30 dB. In our experiments, we did not observe any dependence of the SBSR plot on the scanning dir...

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contrasting

confidence: 38%

Stability of the mode-locked regime in quantum dot lasers

Viktorov

Mandel

Kuntz

et al. 2007

Applied Physics Letters

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“…The quasi-equilibrium Fermi levels are determined by the total carrier density populating the wells [26]. The plasma temperature of electrons and holes evolve according (17) with the carrier-phonon (c-p) scattering rate for electrons and holes, the equilibrium temperature, the total energy for electron and holes [26], and the free carrier absorption (FCA) cross-section. Finally, the dynamics of the total carrier density populating the wells is governed by (18) where is the injection current, the electronic charge, the volume of the active region in the gain section, and the bimolecular and Auger recombination rates, respectively.…”

Section: ) Amplifier Model (Soa)mentioning

confidence: 99%

“…However, it is not always immediate to apply the theoretical predictions into the design of a particular device due to many simplifying hypotheses involved in this type of models. On the other side, fully distributed time-domain models provide a suitable description of the mode-locking dynamics in monolithic [15]- [17] and external cavity [18] devices although, in many cases, the noise properties are unaddressed due to the extensive numerical simulations required. In this paper, we theoretically investigate the noise properties of external-cavity mode-locked semiconductor lasers (ECMLL) using a detailed fully distributed time-domain model.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Timing Jitter in External-Cavity Mode-Locked Semiconductor Lasers

Mulet

Mørk

2006

IEEE J. Quantum Electron.

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Abstract-We develop a comprehensive theoretical description of passive mode-locking in external-cavity mode-locked semiconductor lasers based on a fully distributed time-domain approach. The model accounts for the dispersion of both gain and refractive index, nonlinear gain saturation from ultrafast processes, selfphase modulation, and spontaneous emission noise. Fluctuations of the mode-locked pulses are characterized from the fully distributed model using direct integration of noise-skirts in the phase-noise spectrum and the soliton perturbations introduced by Haus. We implement the model in order to investigate the performance of a MQW buried heterostructure laser. Results from numerical simulations show that the optimum driving conditions for achieving the shortest pulses with minimum timing jitter occur for large reverse bias in the absorber section at an optimum optical bandwidth limited by Gordon-Haus jitter.

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“…There are the lumped-element models (Koumans and van Roijen 1996;Leegwater 1996) and the fully distributed time-domain models (Yu et al 1998). Another approach that is well developed is a travelling wave model (Zhang and Carroll 1992;Radziunas 2006;Bandelow et al 2006). Recently Heck et al (2006) presented a model with a lumped-element approach where the propagation of the pulse through the SOA and the SA were calculated using a distributed time-domain model.…”

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confidence: 99%

Modeling of integrated extended cavity InP/InGaAsP semiconductor modelocked ring lasers

et al. 2008

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In this paper a model and simulation results of integrated semiconductor passively modelocked ring lasers are presented. The model includes nonlinear effects such as two-photon absorption and a non-linear refractive index, a logarithmic gain-carrier relation, and concentration dependent radiative and non-radiative carrier recombination rates. The optical bandwidth of the system is controlled by a digital filter. The model has been used to simulate two geometries of ring modelocked lasers. The first is a symmetric design, where the two counter propagating pulses in the cavity experience the same amplification and absorption. The second is an asymmetric design where the differences for the two directions of pulse propagation are maximised. Simulation results show that a symmetrical cavity shows a several times wider window for its operating parameters for stable modelocking.

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40 GHz Mode-Locked Semiconductor Lasers: Theory, Simulations and Experiment

Cited by 79 publications

References 10 publications

Stability of the mode-locked regime in quantum dot lasers

Stability of the mode-locked regime in quantum dot lasers

Analysis of Timing Jitter in External-Cavity Mode-Locked Semiconductor Lasers

Modeling of integrated extended cavity InP/InGaAsP semiconductor modelocked ring lasers

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