A5085764396- Semiconductor Quantum Structures and Devices
- Photonic and Optical Devices
- Semiconductor Lasers and Optical Devices
- Advanced Semiconductor Detectors and Materials
- Advanced Fiber Laser Technologies
- GaN-based semiconductor devices and materials
- X-ray Diffraction in Crystallography
- Solid State Laser Technologies
- Optical measurement and interference techniques
- Advanced X-ray Imaging Techniques
- Nanowire Synthesis and Applications
- ZnO doping and properties
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Measurement and Metrology Techniques
- Ga2O3 and related materials
- Surface Roughness and Optical Measurements
- Crystallization and Solubility Studies
- Laser Design and Applications
- Heusler alloys: electronic and magnetic properties
- Rural development and sustainability
- Photonic Crystal and Fiber Optics
- Millimeter-Wave Propagation and Modeling
- Radio Frequency Integrated Circuit Design
- Combustion and Detonation Processes
- Nuclear materials and radiation effects
Chinese Academy of Sciences
2004-2024
Institute of High Energy Physics
2016-2024
University of Fukui
2020
State Key Laboratory of Building Safety and Built Environment
2014
Institute of Semiconductors
2004-2011
State Key Laboratory on Integrated Optoelectronics
2005-2011
University of Languages and International Studies
2010
Institute of Solid State Physics
2007-2008
Utsunomiya University
2002
Very low threshold current density InGaAs/GaAs quantum well laser diodes grown by molecular beam epitaxy on InGaAs metamorphic buffers are reported. The lasing wavelength of the ridge waveguide diode with cavity length 1200 µm is centred at 1337.2 nm; 205 A/cm2 room temperature under continuous-wave operation.
Starting from the growth of high-quality 1.3μmGaInNAs∕GaAs quantum well (QW), QW emission wavelength has been extended up to 1.55μm by a combination lowering rate, using GaNAs barriers and incorporating some amount Sb. The photoluminescence properties 1.5μm range GaInNAsSb∕GaNAs QWs are quite comparable 1.3μm QWs, revealing positive effect Sb on improving optical quality QWs. A 1.59μm lasing single-QW laser diode is obtained under continuous current injection at room temperature. threshold...
High-indium-content InxGa1−xAs/GaAs single/multi-quantum well (SQW/MQW) structures have been systematically investigated. By optimizing the molecular-beam epitaxy growth conditions, critical thickness of strained In0.475Ga0.525As/GaAs QWs is raised to 7 nm, which much higher than value given by Matthews and Blakeslee model. The good crystalline quality InGaAs/GaAs MQWs proved x-ray rocking curves. Photoluminescence measurements show that an emission wavelength 1.25 μm at room temperatures...
We report the design, growth, fabrication, and characterization of a GaAs-based resonant-cavity-enhanced (RCE) GaInNAs photodetector operating at 1.55μm. The structure device was designed using transfer-matrix method (TMM). By optimizing molecular-beam epitaxy growth conditions, six quantum wells were used as absorption layers. Twenty-five (25)- 9-pair GaAs∕AlAs-distributed Bragg reflectors grown bottom top mirrors. At 1.55μm, efficiency 33% with full width half maximum 10nm obtained. dark...
Calibration is one of the key issues for Hard X-ray Modulation Telescope (HXMT) on board first Chinese astronomical satellite. As its core sciences are to observe Galactic binaries, transients and diffuse emission, corresponding calibration tasks mainly about energy response effective area. To this end we building two facilities specified needs three scientific payloads HXMT: high telescope (HE), medium (ME) low (LE). By adopting a double crystal monochromator, beam can be extracted with an...
Bragg reflection waveguides (BRWs) have recently been proposed for the development of high performance single mode lasers and nonlinear frequency conversion devices. In this letter, we experimentally demonstrate transverse photonic bandgap operation in a large core BRW laser with low threshold current density (~594 A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) characteristic temperature (T <sub...
In this letter, we demonstrated a top illuminated 1.55 μm metamorphic InGaAs resonant-cavity-enhanced p-i-n photodetector grown on GaAs substrate. The photodetectors were by solid-source molecular beam epitaxy system. high quality linearly graded InxAl0.4Ga1−x−0.4As buffer layer enabled photodiodes to achieve ultralow dark current densities of 2.3×10−6 A/cm2 at 0 V and 4.2×10−5 reverse bias 5 V. A quantum efficiency 84.4% resonant wavelength 1542 nm, full width half maximum about 14 −3 dB...
Effect of rapid thermal annealing on photoluminescence (PL) properties InGaAs, InGaNAs, InGaAsSb, and InGaNAsSb quantum wells (QWs) grown by molecular-beam epitaxy was systematically investigated. Variations PL intensity full width at half maximum were recorded from the samples annealed different conditions. The peak intensities InGaAs InGaNAs QWs initially increase then decrease when temperature increased 600to900°C, but drawing lines InGaAsSb take an “M” shape. enhancement in our are...
Rapid thermal annealing (RTA) has been demonstrated as an important way to improve the crystal quality of GaInNAs(Sb)/GaAs quantum wells. However little investigation made into their application in laser growth, especially at a wavelength 1.55 µm. When GaAs-based is grown, AlGaAs usually used for cladding layers. The growth p-cladding layer takes 30–45 min temperature higher than that GaInNAs(Sb) active region, which affects material quality. To investigate this effect, various post-growth...
A 1.55μm low-temperature-grown GaAs (LT-GaAs) photodetector with a resonant-cavityenhanced structure was designed and fabricated. LT-GaAs layer grown at 200°C used as the absorption layer. Twenty- fifteen-pair GaAs∕AlAs-distributed Bragg reflectors were bottom top mirrors. responsivity of 7.1mA∕W full width half maximum 4nm obtained 1.61μm. The dark current densities are 1.28×10−7A∕cm2 bias 0V 3.5×10−5A∕cm2 reverse 4.0V. transient response measurement showed that photocarrier lifetime in is 220fs.
In the previous studies on roll angle (ROLL) measurements which are based concept of combination a diffraction grating displacement technique and laser heterodyne interferometry, there is always lack ideally functional retro-reflectors corresponding optical configurations resulting in misalignment unconfident monitoring. To overcome this problem, differential-grating plane-mirror interferometer proposed paper, sensing method utilized to promote angular interferometry as reliable ROLL...
Abstract The spherically bent x‐ray crystal analyzer is one of the key optical elements for performing high energy resolution hard spectroscopies based on Rowland circle geometry. To meet requirements Resonant Inelastic X‐ray Scattering (RIXS) program at High Energy Photon Source (HEPS), fourth‐generation synchrotron in Beijing, China, analyzers were fabricated. fabrication processes vacuum‐mounted flat‐diced using home‐designed devices with microporous ceramics are presented. analyzers,...
A systematic Mn L-edge x-ray absorption is carried out on carefully prepared Ga0.946Mn0.054As ferromagnetic semiconductors with varying As2∕Ga flux ratio. It found that the L3 peak of spectroscopy enhanced after low temperature (LT) annealing. Furthermore it shown a more localized electronic structure nearly like d5 high-spin state obtained. can be attributed to breaking MnS–MnI pairs during annealing process. authors present direct evidence for slightly increase substitutional concentration due LT
Deep-level defect-related properties of as-grown and annealed GaN epilayers grown by hydride vapor phase epitaxy (HVPE) are investigated using persistent photoconductivity (PPC) photoluminescence (PL) measurements. PPC phenomena seen in these HVPE-GaN which do not contain the yellow-luminescence (YL) band, suggesting that YL related. The decay kinetics indicates characteristic defects responsible for phenomenon would be different from point defects. structural qualities were characterized...
Circular test is an important tactic to assess motion accuracy in many fields especially machine tool and coordinate measuring machine. There are setup errors due using directly centring of the instrument for both contact double ball bar existed non-contact methods. To solve this problem, algorithm circular function construction based on matrix operation proposed, which not only used solution radial deviation (F) but also should be applied obtain two other evaluation parameters hysteresis...
This paper describes the simulated design for a fed circuit having radial structure use in newly proposed millimeter-wave switched sector-beam antenna. The goal is to realize an ultra-high-speed gigabit-rate wireless LAN. designed achieve purpose that input power from unique RF port at structure's center can be sent any one of selected sectors with maximum under required bandwidth. results show bandwidth S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML"...
In the new developing era, rural vocational education is confronted with wild demands for from different service groups, such as workers, incoming labor force and migrant workers. Their enthusiasm learning, however, harmed because of their short learning time, backward methods low income. The cultivation talents areas will be accelerated if modern educational technology based on computer technique, multimedia applications telecommunication networks finds its way in education, which surely...
A radial fed circuit equipped with a SP8T varactor-mounted waveguide switch was numerically designed and its performances were investigated. The S parameter results obtained for different diameters of the metallic through-hole showed that smaller diameter resulted in wider band. Isolations between ON OFF states higher than 35 dB. Thanks to use varactors switch, fed-circuit structure behaved like an 8-sector array antenna having steerable beamforming ability, which is indispensable not only...
A small sample stretcher for in-situ measurement of angle X-ray scattering (SAXS) was developed, which consists stretch, transmission, detection and control systems. The basic parameters the are: tension ⩾ 400 N, 3 mm/min ⩽ stretching speed 50 mm/min, length 30 mm, stroke 80 resolution = μm. is compact has low convenient remote control. It suitable SAXS measurements on carbon fibers, polyethylene other samples. Such were carried out with high density (HDPE) instrument at 1W2A station Beijing...