scholarly journals Optimized High Performance Characteristics of a designed 450 nm InGaN/AlGaN True Blue Laser Considering Different Injection Current

2020 ◽  
Vol 16 (2) ◽  
Author(s):  
Sayed Muhammod Baker ◽  
Rinku Basak
Keyword(s):  
High Performance ◽  
Maximum Output Power ◽  
Threshold Current ◽  
Injection Current ◽  
Blue Laser ◽  
Performance Characteristics ◽  
Maximum Output ◽  
Modulation Bandwidth ◽  
True Blue ◽  
Material Gain

In this work, the effects on the performance characteristics of a In0.1558Ga0.8442N / Al0.0416Ga0.9584N 3QW separate confinement heterostrcture 450 nm true blue edgeemitting laser are presented by considering different injection current. At the temperature of 300 K, the threshold current of the laser is 11 mA. The peak material gain for the designed laser is obtained as 1106 cm-1 and further used for the analysis of the performance characteristics of the designed doubleheterostructure laser for the variation of injection current. The injection current can be applied to the device is at around 12 to 15 times of the threshold current. At the value of injection current 152 mA, the maximum output power of the laser is 256.4 mW, the maximum resonance frequency is 14.5 GHz and the corresponding modulation bandwidth is 25.3 GHz at the temperature of 300 K.

High Power InAsSb/InAsSbP Laser Diodes Emitting at 3 ∼ 5 μm Range

1996 ◽  
Vol 450 ◽  
Author(s):  
M. Razeghi ◽  
J. Diaz ◽  
H. J. Yi ◽  
D. Wu ◽  
B. Lane ◽  
...  
Keyword(s):  
Active Region ◽  
Energy Gap ◽  
Maximum Output Power ◽  
Multiple Quantum Well ◽  
Laser Diodes ◽  
Chemical Vapor ◽  
Threshold Current ◽  
Multiple Quantum ◽  
Maximum Output ◽  
Double Heterostructure

ABSTRACTWe report metalorganic chemical vapor deposition-grown double heterostructure and multiple quantum well InAsSb/InAsSbP laser diodes emitting at 3 to 4 μm and light emitting diodes up to 5 μm. Maximum output power up to 1 W (from two facets) with differential efficiency above 70 % up to 150 K was obtained from a MQW laser with stripe width of 100 μm and cavity length of 700 μm for emitting wavelength of 3.6 μm at 90 K. Maximum operating temperature up to 220 K with threshold current density of 40 A/cm2 at 78 K were achieved from the double-heterostructure lasers emitting at 3.2 μm. The far-field beam divergence as narrow as 24° was achieved with the use of higher energy gap barrier layers, i.e., lower effective refractive index, in MQW active region. We also discuss the effect of composition-fluctuation in the InAsSb active region on the gain and threshold current of the lasers.

OXIDE-CONFINED VERTICAL-CAVITY SURFACE-EMITTING LASERS

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2740-2744
Author(s):  
W. L. LIU ◽  
L. LI ◽  
J. C. ZHONG ◽  
Y. J. ZHAO ◽  
L. N. ZENG ◽  
...  
Keyword(s):  
Characteristic Temperature ◽  
Maximum Output Power ◽  
Threshold Current ◽  
Cavity Surface ◽  
Maximum Output ◽  
Short Period ◽  
Surface Emitting Lasers ◽  
Vertical Cavity Surface ◽  
Emitting Lasers ◽  
Vertical Cavity

Novel distributed Bragg reflectors (DBRs) with 6-pair- GaAs/AlAs short period superlattice for the oxide-confined vertical-cavity surface-emitting lasers (VCSEL) are designed. They are for the VCSEL that emits at 840 nm and is grown with 34-period n-type mirrors, three-quantum-well active region, and 22-period p-type mirrors. In addition, a 35-nm-layer of Al 0.98 Ga 0.02 As was inserted in the top mirrors for being selectively oxidized. The maximum output power is more than 2 mW with low threshold current of about 2 mA. The fact that the device's threshold current in both CW and pulsed operation depends slightly on the operation temperature shows its higher characteristic temperature (T0).

scholarly journals High performance DC/DC buck converter using sliding mode controller

2019 ◽  
Vol 10 (4) ◽  
pp. 1806
Author(s):  
Mustafa Abbas Fadel Al-Qaisi ◽  
Mohanad A. Shehab ◽  
Ammar Al-Gizi ◽  
Mohammed Al-Saadi
Keyword(s):  
Electromagnetic Interference ◽  
High Performance ◽  
Pulse Width Modulation ◽  
Sliding Mode ◽  
Maximum Output Power ◽  
Buck Converter ◽  
System Stability ◽  
Control Technique ◽  
Sliding Mode Controller ◽  
Maximum Output

<span>This paper investigated the performance of the sliding mode control technique for dc/dc converter using frequency response method. The applications of the step down type switching regulator) buck converter (are found in the devices that use batteries as power source like laptop, cell phones, electric vehicle, and recently, it  has also been used in the renewable energy processing, as a maximum output power can be achieved at higher efficiency. In order to optimize the efficiency and for convenient power management, the issues like power on transients, the effect of load variation, Switching and Electromagnetic interference (EMI) losses has to be overcome for which controllers are used. In the proposed method, pulse width modulation (PWM) based on proportional-integral-derivative sliding mode voltage controller (PID SMVC) is designed for a buck converter and the response for appropriate control parameters has been obtained. The system stability has been examined and analyzed from the performance characteristics, which shows clearly that the buck converter controlled by the sliding mode controller has fast dynamic response and it’s very efficient for various applications.</span>

High Performance Ka-Band InAlN/GaN/AlGaN HFET on SiC

2013 ◽  
Vol 662 ◽  
pp. 284-287
Author(s):  
Xiao Wei Zhang ◽  
Ke Jin Jia ◽  
Yv Long Fang ◽  
Shao Bo Dun ◽  
Zhi Hong Feng ◽  
...  
Keyword(s):  
High Performance ◽  
Maximum Output Power ◽  
Drain Current ◽  
Current Gain ◽  
Maximum Output ◽  
60 Ghz ◽  
Ka Band ◽  
Power Added Efficiency ◽  
Rf Performance ◽  
Power Measurements

Ka-band radio-frequency(RF) performance of a InAlN/GaN/AlGaN HFET on SiC was reported. Based on a detailed delay analysis,a maximum drain current density of 1.12 A/mm was obtained. Power measurements were performed, the maximum output power density is 2.1 W/mm and a power-added efficiency (PAE) is 22.3% at 29 GHz. The current gain cut-off frequency (fT) is 60 GHz, and the power gain cut-off frequency (fMAX) is 105 GHz.

scholarly journals 1.3 μm p-Modulation Doped InGaAs/GaAs Quantum Dot Lasers with High Speed Direct Modulation Rate and Strong Optical Feedback Resistance

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 980
Author(s):  
Xia-Yida MaXueer ◽  
Yi-Ming He ◽  
Zun-Ren Lv ◽  
Zhong-Kai Zhang ◽  
Hong-Yu Chai ◽  
...  
Keyword(s):  
Quantum Dot ◽  
High Speed ◽  
Optical Feedback ◽  
Maximum Output Power ◽  
Threshold Current ◽  
Maximum Output ◽  
Large Signal ◽  
Direct Modulation ◽  
Modulation Rate ◽  
Gaas Quantum Dot

Aiming to realize high-speed optical transmitters for isolator-free telecommunication systems, 1.3 μm p-modulation doped InGaAs/GaAs quantum dot (QD) lasers with a 400 μm long cavity have been reported. Compared with the un-doped QD laser as a reference, the p-doped QD laser emits at ground state, with an ultra-low threshold current and a high maximum output power. The p-doped QD laser also shows enhanced dynamic characteristics, with a 10 Gb/s large-signal direct modulation rate and a 7.8 GHz 3dB-bandwidth. In addition, the p-doped QD laser exhibits a strong coherent optical feedback resistance, which might be beyond −9 dB.

scholarly journals Green Route for Fabrication of Water-Treatable Thermoelectric Generators

2022 ◽  
Vol 2022 ◽  
pp. 1-12
Author(s):  
Shinichi Hata ◽  
Misaki Shiraishi ◽  
Soichiro Yasuda ◽  
Gergely Juhasz ◽  
Yukou Du ◽  
...  
Keyword(s):  
Thermoelectric Power ◽  
Organic Semiconductors ◽  
Thermoelectric Materials ◽  
High Performance ◽  
High Efficiency ◽  
Aqueous Media ◽  
Maximum Output Power ◽  
Maximum Output ◽  
Thermoelectric Generators ◽  
Green Route

Since future energy harvesting technologies require stable supply and high-efficiency energy conversion, there is an increasing demand for high-performance organic thermoelectric generators (TEGs) based on waterproof thermoelectric materials. The poor stability of n-type organic semiconductors in air and water has proved a roadblock in the development of reliable thermoelectric power generators. We developed a simple green route for preparing n-type carbon nanotubes (CNTs) by doping with cationic surfactants and fabricated films of the doped CNTs using only aqueous media. The thermoelectric properties of the CNT films were investigated in detail. The nanotubes doped using a cationic surfactant (cetyltrimethylammonium chloride (CTAC)) retained an n-doped state for at least 28 days when exposed to water and air, indicating higher stability than that for contemporary CNT-based thermoelectric materials. The wrapping of the surfactant molecules around the CNTs is responsible for blocking oxygen and water from attacking the CNT walls, thus, extending the lifetime of the n-doped state of the CNTs. We also fabricated thermoelectric power conversion modules comprising CTAC-doped (n-type) and sodium dodecylbenzenesulfonate- (SDBS-) doped (p-type) CNTs and tested their stabilities in water. The modules retained 80±2.4% of their initial maximum output power (at a temperature difference of 75°C) after being submerged in water for 30 days, even without any sealing fills to prevent device degradation. The remarkable stability of our CNT-based modules can enable the development of reliable soft electronics for underwater applications.

scholarly journals Power and Fuel Economy of a Radial Automotive Thermoelectric Generator: Experimental and Numerical Studies

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2720 ◽  
Author(s):  
Martí Comamala ◽  
Toni Pujol ◽  
Ivan Ruiz Cózar ◽  
Eduard Massaguer ◽  
Albert Massaguer
Keyword(s):  
Output Power ◽  
Fuel Economy ◽  
High Performance ◽  
Waste Heat ◽  
Maximum Output Power ◽  
High Mass ◽  
Maximum Output ◽  
Recent Developments ◽  
Te Modules ◽  
Automotive Thermoelectric Generator

Recent developments of high performance thermoelectric (TE) materials have increased the interest of using this technology to directly convert waste heat into electricity. In the automotive sector, many automotive thermoelectric generators (ATEGs) designs use TE modules (TEMs) with high hot side temperatures to cope with high engine load regimes. Here, we develop a new concept of a radial ATEG that is specifically designed to work with low temperature TEMs, which enables the use of Pb-free modules and reduces the thermal stress of the device. A prototype is built and tested at different regimes in an engine test bench. A numerical model of the ATEG is developed and validated. The consequences of modifying (1) the exchange area between the heat absorber and the exhaust gases and (2) the effective figure of merit of TEMs on the electrical output power and fuel economy are investigated by means of simulations. Results indicate that the maximum fuel economy (1.3%) is not attained at the point of maximum output power (228 W). In terms of fuel economy, the back pressure at the exhaust penalizes high mass flow regimes. We use a dimensionless parameter to analyze the potential of the ATEG for reducing fuel consumption.

DOUBLE SUPPLY, LINEAR, AND HIGH EFFICIENCY PUSH AMPLIFIER DESIGN FOR ENVELOPE TRACKING POWER AMPLIFIERS IN WiMAX APPLICATIONS

2014 ◽  
Vol 23 (08) ◽  
pp. 1450113 ◽  
Author(s):  
MOHAMMAD MOGHADDAM TABRIZI ◽  
NASSER MASOUMI
Keyword(s):  
Output Power ◽  
Power Amplifier ◽  
High Performance ◽  
High Efficiency ◽  
Maximum Output Power ◽  
Total Efficiency ◽  
Maximum Output ◽  
Error Vector Magnitude ◽  
Power Added Efficiency ◽  
Amplifier Design

In this work, a novel and efficient approach is proposed to optimize linearity and efficiency of a power amplifier used in mobile communication applications. A linear and high performance push amplifier is designed and analyzed to extract design equations for an optimum performance. The proposed push amplifier has two sections; an analog section and a switching section. The analog section provides the required linearity and the switching section guarantees the satisfaction of the total efficiency level. Double power supply scheme is used in push amplifiers to enhance its performance. Two separate power supplies are employed for linear and switching sections of push amplifiers which have different voltage levels. The implemented circuit is simulated using HSPICERF with TSMC models for active and passive elements. The proposed power amplifier (PA) provides a maximum output power of 25 dBm and power added efficiency (PAE) as high as 51% at 2.5 GHz operation frequency. At 1-dB compression point, this PA exhibits output power of 25 dBm with 48% PAE and 4.5% error vector magnitude (EVM) which is appropriate for 64QAM OFDM signals.

High Performance 785 nm Wavelength Super-Luminescent Diodes

2011 ◽  
Vol 84-85 ◽  
pp. 594-597
Author(s):  
Si Yu Zhang ◽  
Zhong Liang Qiao ◽  
Xin Gao ◽  
Yi Qu ◽  
Guo Jun Liu ◽  
...  
Keyword(s):  
Emission Spectrum ◽  
Output Power ◽  
High Performance ◽  
Room Temperature ◽  
Continuous Wave ◽  
Ring Cavity ◽  
Maximum Output Power ◽  
Maximum Output ◽  
Full Width ◽  
Half Maximum

High-performance 785 nm wavelength super-luminescent diodes (SLDs) with ring cavity were fabricated. The maximum output power of 100 mW was obtained in continuous wave (CW) mode under room temperature. The full width at half maximum (FWHM) of the emission spectrum was 24 nm.

Characterization of microwave-sintered ceramic composites

1993 ◽  
Vol 51 ◽  
pp. 1136-1137
Author(s):  
X. Zhang ◽  
Y. Pan ◽  
T.T. Meek
Keyword(s):  
Matrix Material ◽  
Maximum Output Power ◽  
Ceramic Matrix Composite ◽  
Ceramic Composites ◽  
Processing Technique ◽  
Structure Characterization ◽  
Alumina Powder ◽  
Maximum Output ◽  
Sintered Ceramic

Industrial microwave heating technology has emerged as a new ceramic processing technique. The unique advantages of fast sintering, high density, and improved materials properties makes it superior in certain respects to other processing methods. This work presents the structure characterization of a microwave sintered ceramic matrix composite.Commercial α-alumina powder A-16 (Alcoa) is chosen as the matrix material, β-silicon carbide whiskers (Third Millennium Technologies, Inc.) are used as the reinforcing element. The green samples consisted of 90 vol% Al2O3 powder and 10 vol% ultrasonically-dispersed SiC whiskers. The powder mixture is blended together, and then uniaxially pressed into a cylindrical pellet under a pressure of 230 MPa, which yields a 52% green density. The sintering experiments are carried out using an industry microwave system (Gober, Model S6F) which generates microwave radiation at 2.45 GHz with a maximum output power of 6 kW. The composites are sintered at two different temperatures (1550°C and 1650°C) with various isothermal processing time intervals ranging from 10 to 20 min.

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