Static Gain Saturation Model of Quantum-Dot Semiconductor Optical Amplifiers

Kim, Jungho; Laemmlin, M.; Meuer, C.; Bimberg, D.; Eisenstein, G.

doi:10.1109/jqe.2008.922325

Cited by 79 publications

(46 citation statements)

References 30 publications

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“…4.7 b. An increase in pump current therefore always increases the maximum output power for which near-linear amplification is possible [BER04,SCH05d,KIM08]. The data stream is encoded by the power level, with P on/off corresponding to one and zero-bits, respectively.…”

Section: Gain Saturationmentioning

confidence: 99%

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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Section: Gain Saturationmentioning

confidence: 99%

Nonlinear and Nonequilibrium Dynamics of Quantum-Dot Optoelectronic Devices

Lingnau

2015

Springer Theses

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“…Its response is controlled by their dynamic behavior which can be studied by the use of a three-level system of REs to describe QD-SOA states for ground state (GS), excited state (ES) and WL state, which is considered as a QW and then can be approximated by a single state. While quasi-Fermi levels in the conduction and valence subbands are typically calculated from the surface carrier density per QD layer, now in some recent researches, both WL and barrier layer are included [9]. The barrier layer considered here is assumed to be in the form of a separate confinement heterostructure layer (SCH).…”

Section: Sb-based Qd-soamentioning

confidence: 99%

“…I n o u r m o d e l , a G a u s s i a n d i s t r i b u t i o n f u n c t i o n i s u s e d t o d e s c r i b e inhomogeneous broadening. Accordingly, the linear gain of QD structures can be written as [9,12] …”

Section: Inhomogeneous Gain Model With Global Quasi-fermi Levelsmentioning

confidence: 99%

“…The average signal photon density S av is given by [14] max   gPn si ng S av wLD L g c pw (9) P in is the input signal power to the SOA, n g is the group refractive index, ћ is the normalized Plank's constant, w p is the peak frequency, D is the strip width, L is the cavity length, c is the free space light speed, g max is the peak material gain taken at the peak frequency. The input signal wavelength is assumed to be injected to the QD SOA at a peak wavelength of GS for each structure.…”

Section: Inhomogeneous Gain Model With Global Quasi-fermi Levelsmentioning

confidence: 99%

See 1 more Smart Citation

The Composition Effect on the Dynamics of Electrons in Sb-Based QD-SOAs

Al-Nashy¹,

Al-Khursan²

2012

Selected Topics on Optical Amplifiers in Present Scenario

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“…This manifests itself in many device properties such as low threshold, 1,2 temperature insensitivity, 3 high speed, 3-5 low noise 6 and narrow linewidth 7 lasers as well as high gain, 8,9 linear 10 and low noise 11,12 optical amplifiers. The superior device characteristics are related to the carrier and gain dynamics that are complex due to the effect of high energy unconfined carriers, which are coupled to the confined carriers in the QDs, 13 and due to the gain inhomogeneity of the self-assembled QDs. 14 Carrier dynamics has been studied often in QD optical amplifiers using short pulse time domain techniques.…”

mentioning

confidence: 99%

Ultra-fast charge carrier dynamics across the spectrum of an optical gain media based on InAs/AlGaInAs/InP quantum dots

et al. 2017

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The charge carrier dynamics of improved InP-based InAs/AlGaInAs quantum dot (QD) semiconductor optical amplifiers are examined employing the multi-wavelength ultrafast pump-probe measurement technique. The transient transmission response of the continuous wave probe shows interesting dynamical processes during the initial 2-3 ps after the pump pulse, when carriers originating from two photon absorption contribute the least to the recovery. The effects of optical excitations and electrical bias levels on the recovery dynamics of the gain in energetically different QDs are quantified and discussed. The experimental observations are validated qualitatively using a comprehensive finite-difference time-domain model by recording the time evolution of the charge carriers in the QDs ensemble following the pulse.

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Static Gain Saturation Model of Quantum-Dot Semiconductor Optical Amplifiers

Cited by 79 publications

References 30 publications

Nonlinear and Nonequilibrium Dynamics of Quantum-Dot Optoelectronic Devices

Nonlinear and Nonequilibrium Dynamics of Quantum-Dot Optoelectronic Devices

The Composition Effect on the Dynamics of Electrons in Sb-Based QD-SOAs

Ultra-fast charge carrier dynamics across the spectrum of an optical gain media based on InAs/AlGaInAs/InP quantum dots

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