scholarly journals Numerical Investigation of the Impact of ITO, AlInN, Plasmonic GaN and Top Gold Metalization on Semipolar Green EELs

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1444
Author(s):  
Maciej Kuc ◽  
Łukasz Piskorski ◽  
Maciej Dems ◽  
Michał Wasiak ◽  
Adam K. Sokół ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Threshold Current ◽  
Partial Replacement ◽  
Structural Modifications ◽  
New Material ◽  
Current Densities ◽  
Emitting Lasers ◽  
P Type ◽  
The Impact ◽  
Cladding Layers

In this paper, we present the results of a computational analysis of continuous-wave (CW) room-temperature (RT) semipolar InGaN/GaN edge-emitting lasers (EELs) operating in the green spectral region. In our calculations, we focused on the most promising materials and design solutions for the cladding layers, in terms of enhancing optical mode confinement. The structural modifications included optimization of top gold metalization, partial replacement of p-type GaN cladding layers with ITO and introducing low refractive index lattice-matched AlInN or plasmonic GaN regions. Based on our numerical findings, we show that by employing new material modifications to green EELs operating at around 540 nm it is possible to decrease their CW RT threshold current densities from over 11 kA/cm2 to less than 7 kA/cm2.

MBE Growth and Characterization of II-VI Blue/Green Laser Diodes Having CW Operation at Room Temperature

1994 ◽  
Vol 340 ◽  
Author(s):  
M.D. Ringle ◽  
D.C. Grillo ◽  
Y. Fan ◽  
L. He ◽  
J. Han ◽  
...  
Keyword(s):  
Room Temperature ◽  
Continuous Wave ◽  
Threshold Current ◽  
Green Laser ◽  
Operating Voltage ◽  
Mbe Growth ◽  
Current Densities ◽  
P Type ◽  
Laser Devices

ABSTRACTWe have obtained continuous-wave laser operation at room temperature from a (Zn,Mg)(S,Se)-based Il-VI separate-confinement heterostructure where injection of holes into the p-type quaternary was achieved through the employment of a Zn(Se,Te) graded-bandgap contact. The laser devices exhibit threshold current densities of below 300 A/cm2 and voltages below 6 V. Issues related to the control of the growth of the quaternary (Zn,Mg)(S,Se) compound, and a proposal to further reducing the laser operating voltage will also be described.

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.

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.

Doping effects in p- and n-type layers of 390-nm InGaN DQW lasers

2015 ◽  
Vol 29 (18) ◽  
pp. 1550118
Author(s):  
Gh. Alahyarizadeh ◽  
M. Amirhoseiny ◽  
Z. Hassan
Keyword(s):  
Active Region ◽  
Current Density ◽  
Slope Efficiency ◽  
Radiative Recombination ◽  
Doping Concentration ◽  
Threshold Current ◽  
Optical Intensity ◽  
Current Densities ◽  
P Type ◽  
Hole Current

The performance characteristics of deep violet InGaN laser diodes (LDs) are theoretically studied with the effects of doping concentrations in p- and n-type layers. Comprehensive study on output performance characteristics such as output power, threshold current, slope efficiency, DQE, and optical intensity, as well as on several internal parameters such as quantum well (QW) carrier densities, electron and hole current densities of deep violet InGaN double quantum well (DQW) lasers, have been done. The simulation results indicate that output power of LD is increased by increasing doping concentration in both n- and p-type layers. it can be due to increased carrier current densities and consequently increased radiative recombination. The results also indicate decrease in slope efficiency and DQE with increasing doping concentration. This situation can be caused by increasing nonradiative recombinations, such as Auger recombination inside and outside the active region, current overflow from the active region, and optical losses. Increasing current overflow from the active region also causes an increase in threshold current. Using higher doping concentration in n-type layers results in increase in electron current density in the n-side and consequently, higher electron flow in the active region. It causes an increase in higher radiative recombination and a higher need for holes and consequently, a higher hole current density in p-type layers. As well as, optical intensity of LDs is increased by increasing the doping concentration.

scholarly journals The Interband Cascade Laser

Photonics ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 75
Author(s):  
Jerry Meyer ◽  
William Bewley ◽  
Chadwick Canedy ◽  
Chul Kim ◽  
Mijin Kim ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Threshold Current ◽  
Cavity Surface ◽  
Operating Characteristics ◽  
Continuous Wave Output Power ◽  
Frequency Combs ◽  
Wall Plug Efficiency ◽  
Infrared Spectral ◽  
Emitting Lasers ◽  
Interband Cascade Lasers

We review the history, development, design principles, experimental operating characteristics, and specialized architectures of interband cascade lasers for the mid-wave infrared spectral region. We discuss the present understanding of the mechanisms limiting the ICL performance and provide a perspective on the potential for future improvements. Such device properties as the threshold current and power densities, continuous-wave output power, and wall-plug efficiency are compared with those of the quantum cascade laser. Newer device classes such as ICL frequency combs, interband cascade vertical-cavity surface-emitting lasers, interband cascade LEDs, interband cascade detectors, and integrated ICLs are reviewed for the first time.

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 Mechanical Properties of Concrete by using M- Sand and Basalt Fibre in Concrete

2020 ◽  
Vol 9 (1) ◽  
pp. 314-317
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
High Performance ◽  
Partial Replacement ◽  
Basalt Fibre ◽  
River Sand ◽  
Split Tensile Strength ◽  
New Material ◽  
The Impact ◽  
Basalt Rock

This paper presents the impact of the basalt fibre in concrete.Basalt fibre is a relatively new material and it is a high performance non-metallic fibre made from basalt rock melted at a high temperature. It is economical and having good strength characteristics, and also resists against temperature and alkaline environment. The Main aim of this paper is to find the compressive, flexural and split tensile strength of Concrete with M-sand and Basalt Fibre. The length of basalt fibre 12mm was used with in the range of 0.1% to 0.3%with total volume of concrete. Due to lack of river sand, it is partially replaced with M-sand by 50%and 60% in this work. This paper shows the enhancement of mechanical properties of concrete by adding Basalt fibre and partial replacement of river sand with M-sand.

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