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Title: GaAs-based long-wavelength semiconductor diode lasers for optical fibre communication
Author: Jin, Chaoyuan
ISNI:       0000 0001 3590 6871
Awarding Body: University of Sheffield
Current Institution: University of Sheffield
Date of Award: 2008
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This thesis presents engineering and physics work on the development of highperformance GaAs-based long wavelength semiconductor diode lasers for optical fiber communication, using materials of InAsjGaAs self-assembled quantum dots and GaInNAsjGaAs quantum wells. In this thesis, the motivation of this research will be discussed and a detailed review of literature up-to-present will be introduced. Firstly, the p-type modulation doped structure has been studied to improve and understand the temperature stabilities of self-assembled InAsjGaAs quantum dot (QO) lasers. A room-temperature negative or infinite characteristic temperature (To) and ultra-low threshold current density (Jth) of 48 Acm -2 are demonstrated for 1.3 /-lm QO lasers. A photon coupling mechanism between the ground and first excited quantum dot states is proposed to account for the different temperature dependences of Jth for the both the p-type modulation doped and undoped QO lasers. Secondly, GaInNAs/GaAs quantum well (QW) lasers with a quaternary barrier structure have been investigated. A very low Jth of 178 Acm-2 has been accomplished in a ridge-waveguide single-QW laser. A high temperature stability with a room temperature To value of 189 K has been demonstrated. For broad area lasers, a very low Jth of 150 Acm-2 for a single-QW laser and a Jth of 529 Acm-2 for a triple-QW laser have been achieved. Finally, the possibilities for achieving 1.55 /-lm emission and lasing based on the InAsjGaAs QOs with a GaAsSb strain reducing layer, GaInNAs multiple-QW with high N-content, InAs/GaAs QOs grown on GaAsSb metamorphic buffer layers and InAs/lnAIGaAs/lnP QOs have been studied in details with some initial results provided.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available