High efficiency and high modal gain InAs/InGaAs/GaAs quantum dot lasers emitting at 1300 nm (original) (raw)
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InAs/InGaAs/GaAs quantum dot lasers of 1.3 μm range with enhanced optical gain
Journal of Crystal Growth, 2003
Near-1.3-mm lasers based on multiple layers (2, 5 and 10) of InAs/InGaAs/GaAs quantum dots with high performance have been grown by molecular beam epitaxy. A record differential efficiency as high as 88% was achieved in laser based on 10 QD layers. Threshold current density of 100-150 A/cm 2 and differential efficiency of 75-80% were achieved simultaneously in the same device. Characteristic temperature of 150 K in 20-501C temperature range was demonstrated for the laser based on 5 QD layers. A steep increase in internal loss with decreasing cavity length was found to limit the highest mirror loss possible for ground state lasing. r
High-modal gain 1300-nm In(Ga)As-GaAs quantum-dot lasers
IEEE Photonics Technology Letters, 2006
A semiconductor laser containing seven InAs-In-GaAs stacked quantum-dot (QD) layers was grown by molecular beam epitaxy. Shallow mesa ridge-waveguide lasers with stripe width of 120 m were fabricated and tested. A high modal gain of 41 cm 01 was obtained at room temperature corresponding to a modal gain of 6 cm 01 per QD layer, which is very promising to enable the realization of 1.3-m ultrashort cavity devices such as vertical-cavity surface-emitting lasers. Ground state laser action was achieved for a 360-m-cavity length with as-cleaved facets. The transparency current density per QD layer and internal quantum efficiency were 13 A/cm 2 and 67%, respectively.
IEEE Journal of Quantum Electronics, 2000
The optical performance of quantum dot lasers with different dots-in-a-well (DWELL) structures is studied as a function of the well number and the indium composition in the InGaAs quantum well (QW) surrounding the dots. While keeping the InAs quantum dot density nearly constant, the internal quantum efficiency , modal gain, and characteristic temperature of 1-DWELL and 3-DWELL lasers with QW indium compositions from 10 to 20% are analyzed. Comparisons between the DWELL lasers and a conventional In 0 15 Ga 0 85 As strained QW laser are also made. A threshold current density as low as 16 A/cm 2 is achieved in a 1-DWELL laser, whereas the QW device has a threshold 7.5 times larger. It is found that and the modal gain of the DWELL structure are significantly influenced by the quantum-well depth and the number of DWELL layers. The characteristic temperature 0 and the maximum modal gain of the ground-state of the DWELL structure are found to improve with increasing indium in the QW. It is inferred from the results that the QW around the dots is necessary to improve the DWELL laser's for the dot densities studied.
Toward 1550-nm GaAs-Based Lasers Using InAs/GaAs Quantum Dot Bilayers
IEEE Journal of Selected Topics in Quantum Electronics, 2000
By choice of appropriate growth conditions and optimization of the strain interactions between two closely stacked InAs/GaAs quantum dot (QD) layers, the emission wavelength of the QDs can be significantly extended, giving room-temperature emission from highly uniform QD ensembles in excess of 1500 nm. These QD bilayers are incorporated into edge-emitting laser structures and room-temperature ground-state lasing at 1420 nm and electroluminescence at 1515 nm are observed. Under high-bias conditions, asymmetric broadening of peaks in the laser gain spectra are observed, extending positive net modal gain from the devices to beyond 1500 nm, and the origin of this broadening is discussed.
High-performance InAs/GaAs quantum dot laser with dot layers grown at 425 oC
Chinese Optics Letters, 2013
We investigate InAs/GaAs quantum dot (QD) lasers grown by gas source molecular beam epitaxy with different growth temperatures for InAs dot layers. The same laser structures are grown, but the growth temperatures of InAs dot layers are set as 425 and 500 • C, respectively. Ridge waveguide laser diodes are fabricated, and the characteristics of the QD lasers are systematically studied. The laser diodes with QDs grown at 425 • C show better performance, such as threshold current density, output power, internal quantum efficiency, and characteristic temperature, than those with QDs grown at 500 • C. This finding is ascribed to the higher QD density and more uniform size distribution of QDs achieved at 425 • C.
Comparison of InAs quantum dot lasers emitting at 1.55 µm under optical and electrical injection
Semiconductor Science and Technology, 2005
InAs/InGaAsP/InP(113)B quantum-dots are studied as active mediums for laser structures emitting near 1.55 µm under optical and electrical injection. In order to precisely tune the emission wavelength of QDs, the double cap growth procedure is used. Laser emission on the ground states is obtained under optical pumping at room temperature. On equivalent structures doped for electrical injection, laser emission is also observed at low temperatures up to 200 K. The difference between the optical and electrical pumping is ascribed to low carrier injection efficiency due to the presence of a 3 nm InP hole blocking barrier at each quantum dot layer which is inherent to the double cap growth procedure. Room temperature laser emission has been reached when the InP first cap layer is substituted by a quaternary GaInAsP (1.18 µm gap) layer in the double cap growth procedure. The threshold current density of the new structure with QD capped only by quaternary is as low as 840 A cm −2 at room temperature.
Applied Physics Letters, 1997
We report on quantum dot ͑QD͒ lasers made of stacked InAs dots grown by metalorganic chemical vapor deposition. Successful growth of defect-free binary InAs/GaAs QDs with high lateral density (d l у4ϫ10 10 cm Ϫ2 ) was achieved in a narrow growth parameter window. The room-temperature photoluminescence ͑PL͒ intensity is enhanced up to a factor of 3 and the PL peak width is reduced by more than 30% when a thin layer of In 0.3 Ga 0.7 As is deposited onto the InAs QDs. A QD laser with a single sheet of such InAs/InGaAs/GaAs QDs exhibits threshold current densities as low as 12.7 and 181 A/cm 2 at 100 and 300 K, respectively. Lasers with threefold stacked QDs show ground-state lasing and allow for cw operation at room temperature.
Optical characteristics of 1.24-μm InAs quantum-dot laser diodes
IEEE Photonics Technology Letters, 2000
The optical characteristics of the first laser diodes fabricated from a single-InAs quantum-dot layer placed inside a strained InGaAs QW are described. The saturated modal gain for this novel laser active region is found to be 9-10 cm 01 in the ground state. Room temperature threshold current densities as low as 83 A/cm 2 for uncoated 1.24-m devices are measured, and operating wavelengths over a 190-nm span are demonstrated.