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High power laser diodes of 2 μm AlGaAsSb/InGaSb type I quantum-wells

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Journal of Semiconductors 2015年第5期36卷 50-53页

作者：廖永平张宇邢军亮魏思航郝宏玥王国伟徐应强牛智川 State Key Laboratory for Superlattices and Microstructures Institute of SemiconductorsChinese Academy of Sciences Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China

2μm A1GaAsSb/InGaSb type-I quantum-well high-power laser diodes （LDs） are grown using molec- ular beam epitaxy. Stripe-type waveguide single LD （single emitter） and array LD （four emitters） devices without facet coatings are fabricated. For the single LDs （single emitter） device, the maximum output power under contin- uous wave （CW） operation is 0.5 W at 10℃ with a threshold current density of 150 A/cm^2 and a slope efficiency of 0.17 W/A, the output powers under the pulse mode in the 5% duty cycles are much higher, up to 0.98 W. For the array LD devices, the maximum output powers are 1.02 W under the CW mode and 3.03 W under the pulse mode at room temperature.

关键词： laser diodes arrays emitters quantum wells

Al-free cladding-layer blue laser diodes with a low aspect ratio in far-field beam pattern

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Journal of Semiconductors 2018年第8期39卷 57-61页

作者： Meixin Feng Qian Sun Jianping Liu Zengcheng Li Yu Zhou Hongwei Gao Shuming Zhang Hui Yang Key Laboratory of Nano-Devices and Applications Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO) Chinese Academy of Sciences School of Nano Technology and Nano Bionics University of Science and Technology of China

c-plane GaN-based blue laser diodes（LDs） were fabricated with Al-free cladding layers（CLs） and deepened etching depth of mesa structure, so the aspect ratio of the far-field pattern（FFP） of the laser beam can be reduced to as low as 1.7, which is nearly the same as conventional AlGa In P-based red LDs. By using GaN CLs,the radiation angle of the laser beam θ⊥ is only 10.1° in the direction perpendicular to the junction plane. After forming a deeply etched mesa, the beam divergence angle parallel to the junction plane of FFP, θ;, increases from4.9° to 5.8°. After using the modified structure, the operation voltage of LD is effectively reduced by 2 V at an injection current of 50 mA, but the threshold current value increases. The etching damage may be one of the main reasons responsible for the increase of the threshold current.

关键词： Al-free cladding layers far-field beam patterns aspect ratio laser diodes

Thermal investigation of high-power GaAs-based laser diodes

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Journal of Semiconductors 2017年第5期38卷 59-61页

作者： Jichuan Liu Cuiluan Wang Suping Liu Xiaoyu Ma National Engineering Research Center for Optoelectronic Devices Institute of SemiconductorChinese Academy of Sciences

The thermal characteristics of high-power AlGaAs/GaAs laser diodes（LDs） at high current（2-10 A）are studied with electrical transient method.The temperature rise increases linearly with the current.The thermal resistance of chip is the largest proportion of total thermal resistance.By increasing the width of the chip from 500 to 800 fim,the temperature rise and thermal resistance decrease by 8.5%and 8.8%,respectively.

关键词： laser diodes high power temperature rise thermal resistance electrical transient method

Suppression of electron leakage in 808 nm laser diodes with asymmetric waveguide layer

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Journal of Semiconductors 2016年第1期37卷 69-72页

作者：李翔赵德刚江德生陈平刘宗顺朱建军侍铭赵丹梅刘炜 State Key Laboratory on Integrated Optoelectronics Institute of Semiconductors Chinese Academy of SciencesBeijing 100083 China

Electron leakage in GaAs-based separately confined heterostructure 808 nm laser diodes （SCH LDs） has a serious influence on device performance. Here, in order to reduce the energy of electrons injected into the quantum well （QW）, an A1GaAs interlayer with a smaller A1 component is added between the active region and the n-side waveguide. Numerical device simulation reveals that when the Al-composition of the A1GaAs interlayer and its thickness are properly elected, the electron leakage is remarkably depressed and the characteristics of LDs are improved, owing to the reduction of injected electron energy and the improvement of QW capture efficiency.

关键词： quantum well laser diodes electron leakage electron energy

975 nm multimode semiconductor lasers with high-order Bragg diffraction gratings

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Journal of Semiconductors 2024年第3期45卷 38-44页

作者： Zhenwu Liu Li Zhong Suping Liu Xiaoyu Ma National Engineering Research Center for Optoelectronic Devices Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China College of Materials Sciences and Opto-Electronic Technology University of Chinese Academy of SciencesBeijing 100049China

The 975 nm multimode diode lasers with high-order surface Bragg diffraction gratings have been simulated and calcu-lated using the 2D finite difference time domain(FDTD)algorithm and the scattering matrix method(SMM).The periods and etch depth of the grating parameters have been optimized.A board area laser diode(BA-LD)with high-order diffraction grat-ings has been designed and fabricated.At output powers up to 10.5 W,the measured spectral width of full width at half maxi-mum(FWHM)is less than 0.5 nm.The results demonstrate that the designed high-order surface gratings can effectively nar-row the spectral width of multimode semiconductor lasers at high output power.

关键词： laser diodes distributed Bragg reflector high order gratings high power laser diodes narrow spectrum width

Experimental Investigation of the Spectrum Characteristics of laser diodes Under Low-Frequency Modulation

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Chinese Journal of lasers 1999年第1期 2-7页

作者： LUO Zhongsheng ZHANG Meidun (National Laboratory on Local Fiber optic Communication Networks and Advance Optical Communication Systems, Shanghai Jiao Tong University, Shanghai, 200030, China)

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关键词： laser diodes low frequency modulation longitudinal mode spectrum

Robust YAG:Ce single crystal for ultra-high efficiency laser lighting

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Journal of Rare Earths 2022年第5期40卷 717-724,I0002页

作者： Yaqian Zhang Jianming Liu Yujie Zhang Haisheng Yang Yanxia Yu Qingyun He Xiaojuan Liang Yongfu Liu Weidong Xiang College of Chemistry and Materials Engineering Wenzhou UniversityWenzhou 325035China Ningbo Institute of Materials Technology and Engineering Chinese Academy of SciencesNingbo 315201China

At present,solid-state laser-driven lighting fabricated with blue laser diode(LD)and phosphor has been greatly developed in high-power lighting applications.The major obstacle is the luminescence saturation threshold of the fluorescence conversion material(YAG:Ce).In this work,we successfully prepared a series of high-quality and robust YAG:Ce single crystals.With high quantum efficiency(QE=92%),regular crystal structure and high thermal conductivity,the single-crystal has excellent ability to deal with high radiation flux and thermal accumulation generated by high power.Matching the single-crystal with the laser,the luminous efficiency up to 274 lm/W and saturation threshold of 12 W/mm^(2) were obtained.In addition,the influence of Ce doping concentration and sample processing conditions on the indicators in laser-driven white lighting was systematically studied.The results are of great significance and are believed to promote the development of solid-state laser-driven lighting.

关键词： YAG:Ce Single-crystal laser diodes Luminous efficiency Saturation threshold Rare earths

Mode characteristics of VCSELs with different shape and size oxidation apertures

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Chinese Physics B 2023年第4期32卷 347-351页

作者：谢新宇李健邱小浪王永丽李川川韦欣 Institute of Semiconductors Chinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Vertical cavity surface emitting laser(VCSELs)as the ideal light source for rubidium(Rb)and cesium(Cs)atomic clocks is analyzed for its mode and polarization control.We fabricated three kinds of shapes:triangular,elliptic,and circular oxidation apertures which also have different sizes.We formed three different shape oxide apertures by wetoxidation with 36μm-39μm circular mesa.Our results show that triangular oxidized-VCSEL has the advantages of mode and polarization selection over elliptic and circular oxide apertures.When triangular oxide-confined VCSELs emit in single mode,the measured side mode suppression ratio(SMSR)is larger than 20 d B and orthogonal polarization suppression ratio achieves 10 d B.Resonant blueshift of VCSELs with triangular and elliptic apertures is observed with the decrease of aperture size.

关键词： semiconductor lasers laser diodes microcavity and microdisk lasers semiconductor-device characterization design modeling

Visible light communication for intelligent transportation systems:A review of the latest technologies

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Journal of Traffic and Transportation Engineering(English Edition) 2021年第4期8卷 483-492页

作者： Khaled Shaaban Md Hosne Mobarok Shamim Khadija Abdur-Rouf Department of Engineering Utah Valley UniversityOremUT 84058United States Department of Electrical and Computer Engineering McGill UniversityMontréalQC H3A 0E9Canada Department of Civil&Architectural Engineering Qatar UniversityDohaQatar

In seeking to improve traffic congestion and safety on roads and highways,there has been an increased interest in intelligent transportation systems(ITS).The emerging visible light communication(VLC)technology is a new candidate to enable wireless access in ITS.The purpose of this study is to present a comprehensive review of the current studies related to VLC.Since VLC facilitates illumination and data communication simultaneously,it reduces energy consumption significantly.Additionally,VLC is immune to electromagnetic interference,provides high data security,and utilizes unregulated visible light spectrum,showing promise as a potentially cheaper alternative to existing radio frequency(RF)based technology.Moreover,recent advances in semiconductor materials and solid-state technologies have enabled the development of efficient light-emitting diodes(LEDs)and laser diodes(LDs)which are used as transmitters in a VLC system.Although 10 s of Gbits/s data rate has been demonstrated in indoor VLC links,successful implementation of it in outdoor environments requires further research to overcome the challenges presented by environmental factors,unwanted lights,non-line of sight communication,directional radiation pattern,frequent fragmentation,and so on.Besides,in recent years,semiconductor LDs have been garnering more attention since they can transmit more data over longer distances due to their high quantum efficiency and modulation bandwidth compared to LEDs.As a result,urban planners,policy-makers,transportation engineers,and vehicle manufacturers are considering LD-based VLC to facilitate vehicle-to-vehicle and vehicle-to-infrastructure communication.Thus,this paper reviews and compares the most recent developments in VLC technologies,identifies their benefits and potential use in ITS applications,discusses the probable barriers for their implementation in our existing transportation infrastructure,and suggests future research directions and recommendations to overcome these challenges.

关键词： Vehicle-to-vehicle(V2V)communication Vehicle-to-infrastructure(V2I) communication Light-emitting diodes laser diodes Internet of things Transportation network