Presentation Transcript
Tuning of InGaAs Dots :Tuning of InGaAs Dots F. Heinrichsdorff et al., 41th EMC St. Barbara (1999)
Outline : Outline Basic Concepts for Long Wavelength Emission QW overgrowth DWELL structures
Growth Issues of MOVPE spacers in QD stacks the role of V/III ratio
Roadmap for GaAs-based Long Wavelength Emission :Roadmap for GaAs-based Long Wavelength Emission
Electronic Properties of QDs : Electronic Properties of QDs
Variation of QD Size and In/Ga Ratio :Variation of QD Size and In/Ga Ratio
Large InAs/GaAs QDs :Large InAs/GaAs QDs
Wavelength Tuning by QW Overgrowth :Wavelength Tuning by QW Overgrowth
Example: QD Overgrowth with InGaAs QW :Example: QD Overgrowth with InGaAs QW Wavelength Tuning by QW Overgrowth
Impact of QD Overgrowth :Impact of QD Overgrowth
DWELL Structures :DWELL Structures
Defects at Overgrown Dot Structures :Defects at Overgrown Dot Structures
InGaAs/GaAs Dots in Gain Media :InGaAs/GaAs Dots in Gain Media
Sample Structures :Sample Structures
Limitation of QD stackability :Limitation of QD stackability 0 25 mm
Growth Interruption after QD Deposition :Growth Interruption after QD Deposition
QD LASER :QD LASER
Roadmap for Further Improvements :Roadmap for Further Improvements
QD-Emission Tuning :QD-Emission Tuning
Laser Designed for 1300 nm Emission :Laser Designed for 1300 nm Emission
Origin of Blue Shift :Origin of Blue Shift
Maintain PL Efficiency :Maintain PL Efficiency
Conclusion :Conclusion Overgrowth of In(Ga)As/GaAs dots with an InGaAs SRLis promising for reaching 1.30 mm emission with MOVPE
Crucial issues to obtain 1.30 mm lasing are - the achievement of a high dot density (rQD, dspacer) - the suppression of emission blueshift during upper-cladding growth
A low V/III ratio suppresses In-Ga interdiffusion