High power temperature-insensitive 1.3 µm InAs/InGaAs/GaAs quantum dot lasers

Mikhrin, S. S.; Kovsh, A. R.; Krestnikov, I. L.; Kozhukhov, A.V.; Livshits, D.; Ledentsov, N. N.; Shernyakov, Yu. M.; Novikov, I. I.; Maximov, M. V.; Ustinov, V. M.; Alfërov, Zh. I.

doi:10.1088/0268-1242/20/5/002

Cited by 153 publications

(59 citation statements)

References 7 publications

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“…Self-assembled In͑Ga͒As QD lasers using p-type modulation doping have recently been examined by a number of groups and have generated much interest due to reports of a temperature insensitive threshold current and increased modulation bandwidth. [7][8][9] The modeling of p-doped quantum dot structures, which predicts the reduced threshold current and improved modulation response due to an increased peak modal gain and differential gain, 10 has been reported, and this modeling is consistent with experimentally observed data including laser wavelength as a function of cavity length. 11 However, the threshold current density measured in most of these p-doped laser structures ͑e.g., Refs.…”

Section: Introductionsupporting

confidence: 59%

Gain in p-doped quantum dot lasers

Smowton

Sandall

Liu

et al. 2007

Journal of Applied Physics

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We directly measure the gain and threshold characteristics of three quantum dot laser structures that are identical except for the level of modulation doping. The maximum modal gain increases at fixed quasi-Fermi level separation as the nominal number of acceptors increases from 0 to 15 to 50 per dot. These results are consistent with a simple model where the available electrons and holes are distributed over the dot, wetting layer, and quantum well states according to Fermi-Dirac statistics. The nonradiative recombination rate at fixed quasi-Fermi level separation is also higher for the p-doped samples leading to little increase in the gain that can be achieved at a fixed current density. However, we demonstrate that in other similar samples, where the difference in the measured nonradiative recombination is less pronounced, p doping can lead to a higher modal gain at a fixed current density.

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Section: Introductionsupporting

confidence: 59%

Gain in p-doped quantum dot lasers

Smowton

Sandall

Liu

et al. 2007

Journal of Applied Physics

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“…Quantum-dot lasers have been theoretically predicted to exhibit lower sensitivity to temperature effects compared to quantum-well devices, due to their confined levels inhibiting thermal escape of optically active carriers to the surrounding reservoir [ARA82]. Experimental findings in some cases confirm an improvement regarding temperature stability, especially in p-doped quantum-dot lasers [OTS04,TAN04,MIK05,SUG05], while other results suggest a sensitivity to temperature in quantum-dot lasers that is comparable to quantum-well devices [KLO99,SHC00]. Taking into account carrier heating and temperature effects can therefore be important for a realistic modeling of quantum-dot optical devices.…”

Section: Quantum-dot Laser Carrier-heating Modelmentioning

confidence: 91%

Nonlinear and Nonequilibrium Dynamics of Quantum-Dot Optoelectronic Devices

Lingnau

2015

Springer Theses

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In this thesis the dynamics and performance of optoelectronic devices based on semiconductor quantum-dots are investigated.In the first part, the dynamics of quantum-dot lasers under external perturbations is discussed. Using a microscopically based balance equation model that incorporates detailed charge-carrier scattering dynamics and the possibility to describe nonequilibrium between intra-band electronic states, the relaxation oscillations of the quantum-dot laser are investigated. Three qualitatively different dynamic regimes are identified in dependence of the scattering rates -the "constantreservoir" regime for slow scattering, the "overdamped" regime, and the "synchronized" regime for high scattering -characterized by a varying degree of nonequilibrium between the quantum-dot and reservoir states.Important differences to conventional lasers are found in the modulation response and the dynamics in optical injection and feedback setups. Common theoretical models and approaches used to describe these applications are shown to yield inaccurate predictions, especially in the "constant-reservoir" and "overdamped" dynamic regimes. An important consequence is that the amplitude-phase coupling in quantum-dot lasers, commonly described by the α-factor, differs from conventional descriptions due to the desynchronization of gain and refractive index. While the α-factor describes bifurcations of fixed points accurately, it fails in describing dynamic solutions and overestimates the extent of complex dynamics. The observed low sensitivity to optical perturbations in quantum-dot lasers can therefore be attributed partly to the charge-carrier nonequilibrium. Three quantum-dot laser models on different levels of sophistication are presented that can accurately describe the quantum-dot nonequilibrium dynamics.In the second part of the thesis, the performance of quantum-dot semiconductor optical amplifiers is investigated, and two types of applications unique to quantum-dots as active medium are discussed. The ground and excited states of the quantum-dots allow an ultra-broad-band amplification of optical data streams. Amplified signals on the ground-state frequencies are shown to generally exhibit higher quality than on the excited state, due to a lower sensitivity of the groundstate to carrier-density variations. Nevertheless the quantum-dot amplifier is found to allow effective amplification on both frequency ranges. Furthermore, a parameter range is identified that allows for a simultaneous amplification of data signals on the ground and excited state in a counter-propagating setup.The long microscopically polarization dephasing times in quantum-dots are found to enable quantum-coherent interactions on a macroscopic scale at room-temperature. By comparison with experiments, the occurrence of Rabi-oscillations by amplification of ultra-short pulses is demonstrated. Quantum-dot based devices could therefore be used for future applications based on quantum-coherent effects.

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“…Quantum-dot (QD) light-emitting devices operated in the near infrared range have been widely investigated in recent years [1][2][3][4]. Due to its unique optical characteristics, high-power and temperature-insensitive QD laser diodes (LDs) have already been fabricated [1,2].…”

Section: Introductionmentioning

confidence: 99%