Growth of high-density 1.06-μm InGaAs/GaAs quantum dots for high gain lasers by molecular beamepitaxy

Growth-temperature dependence of optical spin-injection dynamics in self-assembled InGaAs quantum dots

“…The future direction of high-density QD-based spintronic device development should therefore be focused on at least matching the performance of conventional QD lasers, which will require a lateral dot-density greater than 5 Â 10 10 cm À2 to ensure excellent performance with high optical or modal gains. 26,27 IV. CONCLUSIONS By studying the growth-temperature dependence of the optical spin-injection dynamics in In 0.5 Ga 0.5 As QDs, it has been found that the filling effect associated with the excited majority-spin states in QDs can be suppressed by increasing the dot density through a reduction in growth temperature.…”

Persistent High Polarization of Excited Spin Ensembles During Light Emission in Semiconductor Quantum-Dot-Well Hybrid Nanosystems

“…Minority spins can be continuously injected, while the injection of majority spins is blocked by the filling, which makes the number ratio of both spins closer leading to spin relaxation [23]. High-density QDs were used to overcome the spin blocking [24], which completely agrees with the development of QD lasers [25,26]. Spin-dependent filling can also affect the spin dynamics in the laterally coupled QD systems we investigate in this study.…”

Sub‐1100 nm lasing from post‐growth intermixed InAs/GaAs quantum‐dot lasers

“…InAs/GaAs Qdot lasers possess the distinct advantages of reduced threshold current density, temperature sensitivity, filamentation and mirror degradation, thus enabling the realisation of high-power and high-performance devices [1]. Moreover, InAs/GaAs Qdot emission coverage of ∼1060-1400 nm has been employed for the development of optoelectronic devices not only for optical communications but also for a plethora of multidisciplinary field applications [2]. In particular, the short wavelength emission of ∼ 1060-1200 nm has recently attracted attention because of the possibility of coherent light generation in the green-yellow-orange wavelength band via frequency doubling, a cost-effective and compact device for potential incorporation in pico-projectors, semiconductor laser based solid state lighting etc.…”

“…In particular, the short wavelength emission of ∼ 1060-1200 nm has recently attracted attention because of the possibility of coherent light generation in the green-yellow-orange wavelength band via frequency doubling, a cost-effective and compact device for potential incorporation in pico-projectors, semiconductor laser based solid state lighting etc. [1,2]. This short wavelength region was dominated by the highly strained InGaAs/GaAs and InGaAsN/GaAs multiple-quantum well active region laser designs until recently as-grown (AG) InGaAs/GaAs Qdot based lasers emitting at ∼1060-1100 nm have been reported with high power, temperature stability and high gain [1,3].…”

“…This short wavelength region was dominated by the highly strained InGaAs/GaAs and InGaAsN/GaAs multiple-quantum well active region laser designs until recently as-grown (AG) InGaAs/GaAs Qdot based lasers emitting at ∼1060-1100 nm have been reported with high power, temperature stability and high gain [1,3]. However, the growth process was assisted by various schemes such as tunnelling [3], monolayers periodic depositions of InGaAs and InAs material for InGaAs Qdot self-assembled growth [1], and the height limiting growth method [2], to achieve these wavelengths, which adds complexity and cost to device design and fabrication process.…”