Quantum Dots Lasers Instead of God made crystals Man made crystals Final Project for ECE355 Zhenhua Zhang Content From the bulk heterostructure to quantum dots a history review An attractive nanostructure quantum dots Applications of QDs on laser system InGaAs GaAs 1 3 m QDHS Laser QD 1 3 m VCSELs Future trends Milestones on Heterostructure R Dupuis P Dapkus N Holonyak A Cho H Manasevit P N W Shockley H Kroemer 50 s Z Alferov H Kroemer 60 s MBE MOCVD 70 s 80 s Threshold Current Evolution Growth Technique Bulk HSL LPE QWL MBE MOCVD QWRL QDL MBE MOCVD Growth condition need further optimize QDs Nanostructure Density of states for charge carriers in structures with different dimensionalities Energy diagrams in case of left a single atom center a bulk crystal and right a quantum dot Advantages of QD Laser Electronic Confinement Optical Confinement Narrow Linewidth High Efficiency Ultralow Threshold Current Desity Distributed Feedback Single mode Lasing Temperature Stability Formation of QDs Frankvan der Merve Growth Mode 2 12 1 VolmerWeber Growth Mode 2 12 1 StranskiKrastanow Growth Mode Lattice Mismatch QDs on Different Growth Conditions 2ML 3ML 4ML 6ML InAs InAs InAs InAs InAs QDs on GaAs InGaAs QD Laser on GaAs CW output at 1 3 m Single QD layer as active region w 9 m Lc 1 02mm Peak output 160 W Threshold current 4mA Threshold current density 45 A cm2 CW 4K TCD 6 A cm2 InAs InGaAs QDs VCSEL on GaAs Future Trends Growth Condition Optimization Size shape control Increase QDs density Energy level tailoring Spatial location regulation Tunable QDs laser New materials to cover more spectrum Conclusion History review on heterostructure lasers Properties of quantum dot structures Formation of quantum dot structures Application of QDs in different laser systems Future trends