1.5 micron InAs quantum dot lasers based on metamorphic InGaAs/GaAs heterostructures.

2003 ◽  
Vol 794 ◽  
Author(s):  
V.M. Ustinov ◽  
A.E. Zhukov ◽  
A.R. Kovsh ◽  
N.A. Maleev ◽  
S.S. Mikhrin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Active Region ◽  
Quantum Wells ◽  
Gaas Substrate ◽  
Room Temperature ◽  
Internal Quantum Efficiency ◽  
Characteristic Temperature ◽  
Optical Loss ◽  
Threshold Current ◽  
Temperature Threshold

ABSTRACT1.5 micron range emission has been realized using the InAs quantum dots embedded into the metamorphic InGaAs layer containing 20% of InAs grown by MBE on a GaAs substrate. Growth regimes were optimized to reduce significantly the density of dislocations propagating into the active layer from the lattice mismatched interface. 2 mm long InGaAs/InGaAlAs lasers with 10 planes of quantum dots in the active region showed threshold current density about 1.4 kA/cm2 with the external differential efficiency as high as 38%. Lasing wavelength depends on the optical loss being in the 1.44–1.49 micron range at room temperature. On increasing the temperature the wavelength reaches 1.515 micron at 85C while the threshold current characteristic temperature of 55–60K was estimated. High internal quantum efficiency (η>60%)and low internal losses (α=3–4 cm ) were realized. Maximum room temperature output power in pulsed regime as high as 5.5 W for 100 micron wide stripe was demonstrated. Using the same concept 1.3 micron InGaAs/InGaAlAs quantum well lasers were fabricated. The active region contained quantum wells with high (∼40%) indium content which was possible due to the intermediate InGaAs strain relaxation layer. 1 mm stripe lasers showed room temperature threshold current densities about 3.3 kA/cm (λ=1.29 micron) and 400 A/cm2 at 85K. Thus, the use of metamorphic InGaAs layers on GaAs substrate is a very promising approach for increasing the emission wavelength of GaAs based lasers.

1.5 micron InAs quantum dot lasers based on metamorphic InGaAs/GaAsheterostructures.

2003 ◽  
Vol 799 ◽  
Author(s):  
V. M. Ustinov ◽  
A. E. Zhukov ◽  
A. R. Kovsh ◽  
N. A. Maleev ◽  
S. S. Mikhrin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Active Region ◽  
Quantum Wells ◽  
Gaas Substrate ◽  
Room Temperature ◽  
Internal Quantum Efficiency ◽  
Characteristic Temperature ◽  
Optical Loss ◽  
Threshold Current ◽  
Temperature Threshold

ABSTRACT1.5 micron range emission has been realized using the InAs quantum dots embedded into the metamorphic InGaAs layer containing 20% of InAs grown by MBE on a GaAs substrate. Growth regimes were optimized to reduce significantly the density of dislocations propagating into the active layer from the lattice mismatched interface. 2 mm long InGaAs/InGaAlAs lasers with 10 planes of quantum dots in the active region showed threshold current density about 1.4 kA/cm2 with the external differential efficiency as high as 38%. Lasing wavelength depends on the optical loss being in the 1.44–1.49 micron range at room temperature. On increasing the temperature the wavelength reaches 1.515 micron at 85C while the threshold current characteristic temperature of 55–60K was estimated. High internal quantum efficiency (η>60%) and low internal losses (α=3–4 cm-1 ) were realized. Maximum room temperature output power in pulsed regime as high as 5.5 W for 100 micron wide stripe was demonstrated. Using the same concept 1.3 micron InGaAs/InGaAlAs quantum well lasers were fabricated. The active region contained quantum wells with high (∼40%) indium content which was possible due to the intermediate InGaAs strain relaxation layer. 1 mm stripe lasers showed room temperature threshold current densities about 3.3 kA/cm2 (λ=1.29 micron) and 400 A/cm2 at 85K. Thus, the use of metamorphic InGaAs layers on GaAs substrate is a very promising approach for increasing the emission wavelength of GaAs based lasers.

Shape Engineered InAs Quantum Dots with Stabilized Electronic Properties

2002 ◽  
Vol 737 ◽  
Author(s):  
V. Tokranov ◽  
M. Yakimov ◽  
A. Katsnelson ◽  
K. Dovidenko ◽  
M. Lamberti ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
State Energy ◽  
Growth Parameters ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Temperature Threshold ◽  
Inas Quantum Dots ◽  
Subsequent Heating ◽  
Heating Up

ABSTRACTWe have studied the influence of overgrowth procedure and a few monolayer-thick AlAs overlayer on the properties of self-assembled InAs quantum dots (QDs) using scanning electron microscopy (SEM) and photoluminescence (PL). PL spectroscopy was used to optimize optical properties of the QDs by shape engineering (QD truncation) through adjustment of the thickness of overlayers and temperature of the subsequent heating. QDs with 6 nm - thick overlayer with subsequent heating up to 560°C was found to have the highest PL intensity at room temperature and the lowest FWHM, 29 meV. Ground state energy of the truncated QDs is very stable against variations of growth parameters. 1.23 μm edge-emitting laser of triple-layer QD structure demonstrated room temperature threshold current density, 74 A/cm2.

High-Temperature W Diode Lasers Emitting at 3.3µm

1999 ◽  
Vol 607 ◽  
Author(s):  
L. J. Olafsen ◽  
W. W. Bewley ◽  
I. Vurgaftman ◽  
C. L. Felix ◽  
E. H. Aifer ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Room Temperature ◽  
Optical Pumping ◽  
Diode Lasers ◽  
Characteristic Temperature ◽  
Threshold Current ◽  
Type Ii ◽  
Operating Characteristics ◽  
Current Densities ◽  
Cladding Layers

AbstractW lasers based on type-II antimonides were recently operated nearly to room temperature under the conditions of cw optical pumping. However, the development of electrically pumped mid-infrared lasers has not yet reached the same level of performance. This is largely related to the more challenging task of simultaneously optimizing the doping/transport and gain/optical properties of the devices. Here we report a demonstration of type-II mid-IR diode lasers employing W active quantum wells. Laser structures with 5 or 10 active periods sandwiched between broadened-waveguide separate confinement regions and quaternary optical cladding layers were processed into 100-µm-wide stripes, cleaved into 1-mm-long cavities, and mounted junction side down. For 0.5-1 µs pulses at a repetition rate of 200 Hz, lasing was obtained up to a maximum operating temperature of 310 K, where the emission wavelength was 3.27 µm. The threshold current densities were 110 A/cm2and 25 kA/cm2 at 78 and 310 K, respectively. The characteristic temperature, To, was 48 K for temperatures between 100 and 280 K. Operation in cw mode was obtained to 195 K, with threshold current densities of 63 A/cm2and 1.4 kA/cm2at 78 and 195 K, respectively, with To = 38 K between 78 and 195 K. Significant further improvements in the operating characteristics are expected once the optimization of the designs and fabrication procedures is complete.

scholarly journals Luminescence from Droplet-Etched GaAs Quantum Dots at and Close to Room Temperature

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 690
Author(s):  
Leonardo Ranasinghe ◽  
Christian Heyn ◽  
Kristian Deneke ◽  
Michael Zocher ◽  
Roman Korneev ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Penetration Depth ◽  
Gaas Substrate ◽  
Room Temperature ◽  
Green Laser ◽  
Significant Loss ◽  
Blue Laser ◽  
Ambient Conditions ◽  
Thermal Escape ◽  
Intensity Loss

Epitaxially grown quantum dots (QDs) are established as quantum emitters for quantum information technology, but their operation under ambient conditions remains a challenge. Therefore, we study photoluminescence (PL) emission at and close to room temperature from self-assembled strain-free GaAs quantum dots (QDs) in refilled AlGaAs nanoholes on (001)GaAs substrate. Two major obstacles for room temperature operation are observed. The first is a strong radiative background from the GaAs substrate and the second a significant loss of intensity by more than four orders of magnitude between liquid helium and room temperature. We discuss results obtained on three different sample designs and two excitation wavelengths. The PL measurements are performed at room temperature and at T = 200 K, which is obtained using an inexpensive thermoelectric cooler. An optimized sample with an AlGaAs barrier layer thicker than the penetration depth of the exciting green laser light (532 nm) demonstrates clear QD peaks already at room temperature. Samples with thin AlGaAs layers show room temperature emission from the QDs when a blue laser (405 nm) with a reduced optical penetration depth is used for excitation. A model and a fit to the experimental behavior identify dissociation of excitons in the barrier below T = 100 K and thermal escape of excitons from QDs above T = 160 K as the central processes causing PL-intensity loss.

InAs Quantum Dots in AlAs/GaAs Short Period Superlattices: Structure, Optical Characteristics and Laser Diodes

2001 ◽  
Vol 707 ◽  
Author(s):  
Vadim Tokranov ◽  
M. Yakimov ◽  
A. Katsnelson ◽  
K. Dovidenko ◽  
R. Todt ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Inas Quantum Dots ◽  
Transmission Electron ◽  
Short Period ◽  
Short Period Superlattices ◽  
Emitting Lasers ◽  
Cladding Layers

ABSTRACTThe influence of two monolayer - thick AlAs under- and overlayers on the formation and properties of self-assembled InAs quantum dots (QDs) has been studied using transmission electron microscopy (TEM) and photoluminescence (PL). Single sheets of InAs QDs were grown inside a 2ML/8ML AlAs/GaAs short-period superlattice with various combinations of under- and overlayers. It was found that 2.4ML InAs QDs with GaAs underlayer and 2ML AlAs overlayer exhibited the lowest QD surface density of 4.2x1010 cm-2 and the largest QD lateral size of about 19 nm as compared to the other combinations of cladding layers. This InAs QD ensemble has also shown the highest room temperature PL intensity with a peak at 1210 nm and the narrowest linewidth, 34 meV. Fabricated edge-emitting lasers using triple layers of InAs QDs with AlAs overlayer demonstrated 120 A/cm2 threshold current density and 1230 nm emission wavelength at room temperature. Excited state QD lasers have shown high thermal stability of threshold current up to 130°C.

Magneto-Photoluminescence Study of InGaAs/GaAs Quantum Wells and Quantum Dots Grown on (111)B GaAs Substrate

2000 ◽  
Vol 39 (Part 1, No. 6A) ◽  
pp. 3286-3289 ◽  
Author(s):  
Shing-Long Tyan ◽  
Philip A. Shields ◽  
Robin J. Nicholas ◽  
Fu-Yi Tsai ◽  
Chien-Ping Lee
Keyword(s):  
Quantum Dots ◽  
Quantum Wells ◽  
Gaas Substrate ◽  
Photoluminescence Study

InAs quantum dots in AlAs/GaAs short period superlattices: structure, optical characteristics and laser diodes

2001 ◽  
Vol 692 ◽  
Author(s):  
Vadim Tokranov ◽  
M. Yakimov ◽  
A. Katsnelson ◽  
K. Dovidenko ◽  
R. Todt ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Inas Quantum Dots ◽  
Transmission Electron ◽  
Short Period ◽  
Short Period Superlattices ◽  
Emitting Lasers ◽  
Cladding Layers

AbstractThe influence of two monolayer - thick AlAs under- and overlayers on the formation and properties of self-assembled InAs quantum dots (QDs) has been studied using transmission electron microscopy (TEM) and photoluminescence (PL). Single sheets of InAs QDs were grown inside a 2ML/8ML AlAs/GaAs short-period superlattice with various combinations of under- and overlayers. It was found that 2.4ML InAs QDs with GaAs underlayer and 2ML AlAs overlayer exhibited the lowest QD surface density of 4.2×1010 cm-2 and the largest QD lateral size of about 19 nm as compared to the other combinations of cladding layers. This InAs QD ensemble has also shown the highest room temperature PL intensity with a peak at 1210 nm and the narrowest linewidth, 34 meV. Fabricated edge-emitting lasers using triple layers of InAs QDs with AlAs overlayer demonstrated 120 A/cm2 threshold current density and 1230 nm emission wavelength at room temperature. Excited state QD lasers have shown high thermal stability of threshold current up to 130°C.

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