Modelling of the effects of conduction band fluctuations caused by nitrogen clustering in GaInNAs materials

2013

Phys. Status Solidi C

It has been observed experimentally that the band edge photoluminescence (PL) of GaxIn1‐xNyAs1‐yquantum well (QW) materials is broadened due to compositional fluctuations with N distribution. These fluctuations can be modelled as quantum dot‐like region at the conduction band minimum in as‐grown GaInNAs/GaAs QWs. We have developed a rate‐equation approach to describe the distribution of electrons in the QW and QD‐like fluctuations which include the carrier recombination from both the conventional 2D QW layer and the inhomogeneous dot‐like fluctuations. The electron dynamics in the QW and QDs states are examined and the resulting carrier population and broadband gain is derived for a single QW. This is then applied to the design of a broadband gain multi‐QW semiconductor optical amplifier (SOA). (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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mentioning

confidence: 97%

Tailoring broadband gain incorporating quantum dot fluctuations for a GaInNAs semiconductor optical amplifier

2013

Phys. Status Solidi C

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“…To derive gain from this model is fundamentally difficult requiring improved treatments which treat a complex bandstructure [1]. In addition, spatial fluctuations of N cause a lowering of the conduction band and a possible trapping of electrons in these quantum-dot (QD)-like fluctuations [2]. Also the position of the N within the QW affects the strength of its coupling to the conduction band [3].…”

mentioning

confidence: 99%

Optical gain studies for dilute nitrides for application in broad band SOAs

2011 13th International Conference on Transparent Optical Networks

2011

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EXTENDED ABSTRACTGaInNAs/GaAs quantum wells emitting around 1300 nm have been the subject of intense interest for optical data-and tele-communications applications. Indeed the observation of 1550 nm emission with GaInNAsSb has increased their potential usefulness. Their ability to be made into VCSELs using AlGaAs-based DBRs, their high gain, high differential gain and their fast modulation speed offers much. The study of the material aspects of dilute nitride, where the nitrogen acts as a defect, not fully incorporating into the lattice, has been incorporated within the Band Anti-crossing (BAC) model. To derive gain from this model is fundamentally difficult requiring improved treatments which treat a complex bandstructure [1]. In addition, spatial fluctuations of N cause a lowering of the conduction band and a possible trapping of electrons in these quantum-dot (QD)-like fluctuations [2]. Also the position of the N within the QW affects the strength of its coupling to the conduction band [3]. All of these effects must be understood and can be used to tailor the material gain of the dilute nitrides. In this study we consider the possibilities to tailor broad-band for the design of SOAs in the 1300 nm window. We include: i) the effect of the mixing of the N defect-like states(single, pair and cluster states) with the GaInAs band, which create optical features at the defect-like states after mixing, ii) compositional fluctuations of the N to create 20 -40 meV QDs and iii) positional fluctuations within the QW to broaden the gain. All of these effects are considered for one quantum well and then multi-quantum systems are considered to create a broad flat gain spectrum for SOA design. 0.9 0.95 1 1.05 1.1

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Broad-band gain incorporating quantum dot fluctuations for a GaInNAs semiconductor optical amplifier

2012 5th International Conference on Computers and Devices for Communication (CODEC)

2012