scholarly journals Рабочие характеристики полупроводниковых лазеров на квантовых ямах в зависимости от ширины волноводной области

2021 ◽  
Vol 55 (12) ◽  
pp. 1229
Author(s):  
З.Н. Соколова ◽  
Н.А. Пихтин ◽  
С.О. Слипченко ◽  
Л.В. Асрян
Keyword(s):  
Output Power ◽  
Current Density ◽  
Optical Loss ◽  
Optical Power ◽  
Pump Current ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Operating Characteristics ◽  
Optical Confinement ◽  
Cladding Layers

Operating characteristics of semiconductor quantum well (QW) lasers are theoretically studied in terms of the thickness of the waveguide region [optical confinement layer (OCL)]. We calculate the maximum modal gain, optical confinement factor (in QW, OCL, and cladding layers), threshold current density, electron and hole densities (in QW and OCL), internal optical loss (in QW, OCL, and cladding layers), internal differential quantum efficiency, stimulated and spontaneous recombination currents, and output optical power of the laser as functions of the OCL thickness. It is shown that up to the pump current density 50 kA/cm2 the output power of the considered lasers depends only slightly on the OCL thickness in the range of thicknesses 1.5–2.8 m. This result is important for designing high brightness lasers as broadened waveguides are used in such lasers to attain low beam divergence. At high pump current densities, the output power is shown to have a maximum as a function of the OCL thickness.

scholarly journals Performance deterioration of GaN-based laser diode by V-pits in the upper waveguide layer

Nanophotonics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 667-674
Author(s):  
Feng Liang ◽  
Degang Zhao ◽  
Desheng Jiang ◽  
Wenjie Wang ◽  
Zongshun Liu ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Current Density ◽  
Optical Loss ◽  
Optical Power ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Device Performance ◽  
Nonradiative Recombination ◽  
Calculation Results ◽  
Performance Deterioration

AbstractThe effect of V-pits in the upper waveguide (UWG) on device performance of GaN-based laser diodes (LDs) has been studied. Experimental results demonstrate that in comparison with the LDs with u-In0.017Ga0.983N/u-GaN multiple UWG or u-In0.017Ga0.983N one, the LDs with a single u-GaN UWG has the best device performance. They have a smaller threshold current density, and a larger and more stable output optical power. The lowest threshold current density is as low as 1.3 kA/cm2, and the optical power reaches to 2.77 W. Furthermore, atomic force microscopy suggests that the deterioration of device performance of former kinds of devices may be attributed to the increase of V-pits’ size and quantity in the undoped-In0.017Ga0.983N UWG layer, and these V-pits could introduce more nonradiative recombination centers and exacerbate the inhomogeneity of injection current. Moreover, theoretical calculation results indicate that the increase of leakage current and optical loss are additional reasons for the device performance deterioration, which may be caused by a reduction of the potential barrier height for electrons in the quantum wells and by an increased background electron concentration in UWG.

Growth, Fabrication, and Operating Characteristics of Ultra-Low Threshold Current Density 1.3 µm Quantum Dot Lasers

2005 ◽  
Vol 44 (4B) ◽  
pp. 2520-2522 ◽  
Author(s):  
Sumon K. Ray ◽  
Kristian M. Groom ◽  
Richard A. Hogg ◽  
Hui-Yun Liu ◽  
Ian R. Sellers ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Current Density ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Quantum Dot Lasers ◽  
Operating Characteristics ◽  
Low Threshold

scholarly journals Numerical Design and Frequency Response of all group-IV alloys based MQW Transistor Laser

2021 ◽  
Author(s):  
Ravi Ranjan ◽  
Prakash Pareek ◽  
Mukul Kumar Das ◽  
Saurabh Kumar Pandey
Keyword(s):  
Frequency Response ◽  
Current Density ◽  
Multiple Quantum Well ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Photon Density ◽  
Multiple Quantum ◽  
Optical Confinement ◽  
Modal Gain ◽  
Transistor Laser

Abstract In this work, a theoretical model is developed for n-p-n mid-infrared transistor laser (TL) with strain-balanced Ge0.85Sn0.15 multiple quantum well (MQW) structure in the base. Variation of optical confinement factor, modal gain and threshold current density have been rigorously investigated for different number of QWs (N) in MQW structure. The result shows that overall optical confinement factor and modal gain increase with N. The frequency response of MQWTL for common base (CB) configuration is estimated from small signal relationship between the photon density and emitter current density by solving laser rate equation and continuity equation considering the virtual states as a conversion mechanism. Increment of N causes modulation bandwidth to initially increase and then decreases with N, which reveals a shifting of device nature for higher values of N. The results also suggest that on judicious selection of N, the proposed device can become a viable monolithic light source.

Extremely low threshold current density InGaAs/GaAs/AIGaAs strained SQW laser grown by MBE with As2

1996 ◽  
Vol 74 (S1) ◽  
pp. 1-4 ◽  
Author(s):  
M. Dion ◽  
Z. R. Wasilewski ◽  
F. Chatenoud ◽  
V. K. Gupta ◽  
A. R. Pratt ◽  
...  
Keyword(s):  
Quantum Well ◽  
Current Density ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Single Quantum Well ◽  
Graded Index ◽  
Quantum Well Laser ◽  
Gaas Barrier ◽  
Low Threshold ◽  
Cladding Layers

In this report, we present data on an InGaAs/GaAs strained single quantum well laser with the lowest reported threshold current density to date, namely 44 A cm−2 for a 3 mm cavity length. This was grown by solid-source molecular-beam epitaxy with the arsenic dimer, As2. The structure is that of a graded-index, separate-confinement heterostructure with a single strained InGaAs quantum well, sandwiched between GaAs barrier layers and AlGaAs cladding layers. The wavelength of the lasers was around 985 nm, and the internal efficiency and losses were 69% and 0.70 cm−1, respectively. In addition, data on the uniformity of our lasers, which are grown on rotating 2 in substrates (1 in = 2.54 cm), show drops in photoluminescence emission wavelength and layer thickness of less than 4 nm and 4%, respectively, from the centre to the edge of the wafer and very little compositional change.

InGaN/GaN/AlGaN-Based Leds and Laser Diodes

1998 ◽  
Vol 537 ◽  
Author(s):  
S. Nakamura ◽  
M. Senoh ◽  
S. Nagahama ◽  
N. Iwasa ◽  
T. Matushita ◽  
...  
Keyword(s):  
Quantum Well ◽  
Leakage Current ◽  
Output Power ◽  
Current Density ◽  
Laser Diodes ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Nonradiative Recombination ◽  
Window Region ◽  
Recombination Centers

AbstractInGaN quantum-well-structure blue LEDs were grown on epitaxially laterally overgrown GaN (ELOG) and sapphire substrates. The output power of both LEDs was as high as 6 mW at a current of 20 mA. The LED on sapphire had a considerable amount of leakage current in comparison with that on ELOG. These results indicate that In composition fluctuation is not caused by threading dislocations (TDs), free carriers are captured by radiative recombination centers before they are captured by nonradiative recombination centers in InGaN, and that the dislocations form the leakage current pathway in InGaN. Red LED with an emission peak wavelength of 650 nm was fabricated by increasing the In composition and thickness of InGaN well layer. When the laser diodes (LD) was formed on the GaN layer above the SiO2 mask region, the threshold current density was as low as 3 kAcm-2. When the LD was formed on the window region, the threshold current density was as high as 6 to 9 kAcm-2. There is a possibility that a leakage current due to a large number of TDs caused the high threshold current density on the window region. InGaN multi-quantum-well (MQW) structure LDs grown on the ELOG substrate showed an output power as high as 420 mW under RT-CW operation. The longest lifetime of 9,800 hours at a constant output power of 2 mW was achieved. The InGaN MQW LDs were fabricated on a GaN substrate. The fundamental transverse mode was observed up to an output power of 80 mW.

Decreasing the threshold current density in Si lasers fabricated by using dressed-photons

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
H. Tanaka ◽  
T. Kawazoe ◽  
M. Ohtsu ◽  
K. Akahane
Keyword(s):  
Spontaneous Emission ◽  
Current Density ◽  
Optical Gain ◽  
Gain Coefficient ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Annealing Process ◽  
Optical Confinement ◽  
Light Waveguide ◽  
Soi Technology

Abstract:We fabricated a silicon (Si) laser by applying a dressed-photon–phonon assisted annealing process to a ridge-type light waveguide that we fabricated via siliconon- insulator (SOI) technology. We also evaluated a nearinfrared Si photodiode having optical gain to estimate the differential gain coefficient for designing lightwaveguides. We designed light waveguides having a thickness of 15 μm to realize a large optical confinement factor. The fabricated Si laser oscillated at a wavelength of 1.4 μm. The intensity of amplified spontaneous emission (ASE) lightwas too low to be observed, because the threshold current density was so low that the Si laser started oscillating immediately after ASE occurred. The threshold current density for oscillation was estimated to be 40 A/cm

scholarly journals InGaN/GaN/AlGaN-Based Leds and Laser Diodes

1999 ◽  
Vol 4 (S1) ◽  
pp. 1-17 ◽  
Author(s):  
S. Nakamura ◽  
M. Senoh ◽  
S. Nagahama ◽  
N. Iwasa ◽  
T. Matushita ◽  
...  
Keyword(s):  
Quantum Well ◽  
Leakage Current ◽  
Output Power ◽  
Current Density ◽  
Laser Diodes ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Nonradiative Recombination ◽  
Window Region ◽  
Recombination Centers

InGaN quantum-well-structure blue LEDs were grown on epitaxially laterally overgrown GaN (ELOG) and sapphire substrates. The output power of both LEDs was as high as 6 mW at a current of 20 mA. The LED on sapphire had a considerable amount of leakage current in comparison with that on ELOG. These results indicate that In composition fluctuation is not caused by threading dislocations (TDs), free carriers are captured by radiative recombination centers before they are captured by nonradiative recombination centers in InGaN, and that the dislocations form the leakage current pathway in InGaN. Red LED with an emission peak wavelength of 650 nm was fabricated by increasing the In composition and thickness of InGaN well layer. When the laser diodes (LD) was formed on the GaN layer above the SiO2 mask region, the threshold current density was as low as 3 kAcm−2. When the LD was formed on the window region, the threshold current density was as high as 6 to 9 kAcm−2. There is a possibility that a leakage current due to a large number of TDs caused the high threshold current density on the window region. InGaN multi-quantum-well (MQW) structure LDs grown on the ELOG substrate showed an output power as high as 420 mW under RT-CW operation. The longest lifetime of 9,800 hours at a constant output power of 2 mW was achieved. The InGaN MQW LDs were fabricated on a GaN substrate. The fundamental transverse mode was observed up to an output power of 80 mW.

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