Simultaneous measurements of electron and hole sweep-out from quantum wells and modeling of photoinduced field screening dynamics

Cavaillès, Jean; Miller, David A. B.; Cunningham, J. E.; Wa, P. Li Kam; Miller, A.

doi:10.1109/3.159555

Cited by 75 publications

(22 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The solid, dashed, and dot-dashed curves show calculated total, thermionic, and tunneling escape times correspondingly. The experimental points (filled circles) are taken from Cavailles et al [20] and the open squares are calculation results by Lefebvre and Anwar [13]. The detailed description of the model and experimental structures are given in the text.…”

Section: Escape Timementioning

confidence: 99%

Photocarrier escape time in quantum-well light-absorbing devices: effects of electric field and well parameters

Nikolaev

Avrutin

2003

IEEE J. Quantum Electron.

View full text Add to dashboard Cite

Article:Nikolaev, V V and Avrutin, E A orcid.org/0000-0001- 5488-3222 (2003) ReuseUnless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. Abstract-We analyze the dependence of the carrier escape time from a single-quantum-well optoelectronic device on the aplied electric field and well width and depth. For this purpose, a new simple and computationally efficient theory is developed. This theory is accurate in the case of electrons, and the assessment of the applicability for holes is given. Semi-analytical expressions for the escape times are derived. Calculations are compared to experimental results and previous numerical simulations. Significant correlations between the position of quantum-well energy levels and the value of the escape time are found. The main escape mechanism at room temperature is established to be thermally assisted tunneling/emission through near-barrier-edge states. The formation of a new eigenstate in the near-barrier-edge energy region is found to reduce the electron escape time significantly, which can be used for practical device optimization.Index Terms-Optoelectronic devices, quantum wells (QWs), saturable absorbers.

show abstract

Section: Escape Timementioning

confidence: 99%

Photocarrier escape time in quantum-well light-absorbing devices: effects of electric field and well parameters

Nikolaev

Avrutin

2003

IEEE J. Quantum Electron.

View full text Add to dashboard Cite

show abstract

“…4 Time-resolved pump-probe spectroscopy is a very useful technique to investigate the fundamental timescales and underlying dynamical processes occurring in such absorbers; a notable example being the demonstration of the dynamical role of different carrier types for QW devices. 5 More recently, similar techniques were applied to QD structures to explain the nature of tunneling processes at high reverse bias voltages 6 and to demonstrate the electroabsorption properties of a bilayer QD waveguide. 7 In this letter, the nonlinear recovery of QD based reversed-biased waveguide absorbers is analyzed using a single color pump-probe technique.…”

mentioning

confidence: 99%

Intradot dynamics of InAs quantum dot based electroabsorbers

Piwoński

Pulka

Madden

et al. 2009

Applied Physics Letters

View full text Add to dashboard Cite

The carrier relaxation and escape dynamics of InAs/GaAs quantum dot waveguide absorbers is studied using heterodyne pump-probe measurements. Under reverse bias conditions, we reveal differences in intradot relaxation dynamics, related to the initial population of the dots' ground or excited states. These differences can be attributed to phonon-assisted or Auger processes being dominant for initially populated ground or excited states, respectively. © 2009 American Institute of Physics. ͓DOI: 10.1063/1.3106633͔The physics of quantum dot ͑QD͒ based optical devices has been studied intensively due to their interesting blend of atomic and solid state properties.1 Recently, attention has been focused on their absorption properties and has led to QD materials finding favor in such applications as monolithic mode-locked lasers, 2 electroabsorption modulators, 3 and saturable absorber mirrors. 4 Time-resolved pump-probe spectroscopy is a very useful technique to investigate the fundamental timescales and underlying dynamical processes occurring in such absorbers; a notable example being the demonstration of the dynamical role of different carrier types for QW devices. 5 More recently, similar techniques were applied to QD structures to explain the nature of tunneling processes at high reverse bias voltages 6 and to demonstrate the electroabsorption properties of a bilayer QD waveguide. 7In this letter, the nonlinear recovery of QD based reversed-biased waveguide absorbers is analyzed using a single color pump-probe technique. Either the dots' ground state ͑GS͒ or excited state ͑ES͒ is initially populated thus increasing the transmission, and the resulting absorption recovery dynamics is recorded. The recovery dynamics is observed to be dependent on the initial population of the dots' energy states. The difference in recovery dynamics can be understood by the ES to GS carrier relaxation process being phonon assisted when the dots are initially populated in the GS, while it is Auger related when the dots' ES is initially populated.In our experiments, we study intradot relaxation processes as a function of reverse bias using time-resolved spectroscopy. The QD waveguide absorber was 1 mm long, had 4 m width ridges together with tilted, antireflection coated facets. It was fabricated from a material that included six stacks of InAs/GaAs QDs in a dots-in-a-well structure, grown by Zia Inc. ͑see Ref. 8 for further details of the material and experimental technique͒. To summarize, the GS and ES peaks appear at 1320 and 1250 nm, respectively. The pump-probe differential transmission was measured using a heterodyne detection technique. Pulses of about 600 fs width at either 1320 or 1250 nm were obtained from a titaniumsapphire pumped, optical parametric oscillator and split into three beams: reference, pump, and probe ͑260 fJ pump pulse energy, 13 fJ probe pulse energy͒. After propagation through the waveguide absorber with suitable delays, the frequency shifted probe and reference beams were overlapped on a detector, and the amp...

show abstract

“…When running at O 1 , whenever there is absorption in the modulator there is also substantial electric field over the quantum wells. The electric field tends to cause the carriers to escape from the wells rapidly [13] [14], and so they tend not to build up in the wells.…”

Section: Quantum Well Modulatorsmentioning

confidence: 99%