A5088516414- GaN-based semiconductor devices and materials
- Semiconductor Quantum Structures and Devices
- Ga2O3 and related materials
- Quantum and electron transport phenomena
- Advanced Fiber Laser Technologies
- Semiconductor Lasers and Optical Devices
- Advanced Fiber Optic Sensors
- Semiconductor materials and devices
- Photonic and Optical Devices
- Semiconductor materials and interfaces
- ZnO doping and properties
- Nanowire Synthesis and Applications
- Optical Coatings and Gratings
- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Photonic Crystal and Fiber Optics
- Advanced Surface Polishing Techniques
- Advanced NMR Techniques and Applications
- NMR spectroscopy and applications
- Laser Material Processing Techniques
- Power Systems and Renewable Energy
- Electron Spin Resonance Studies
- Advanced Sensor and Energy Harvesting Materials
- Copper-based nanomaterials and applications
- Photochemistry and Electron Transfer Studies
Chinese Academy of Sciences
2003-2024
Xiamen University
2016-2024
Changchun Institute of Optics, Fine Mechanics and Physics
2019-2024
Fuzhou University
2016-2017
State Key Laboratory on Integrated Optoelectronics
2017
Jilin University
2017
City University
2014
Nanjing University
2000-2005
Shanghai Institute of Technical Physics
2003-2005
Collaborative Innovation Center of Advanced Microstructures
2004
In this letter, a sapphire fiber Bragg grating (SFBG) is fabricated by femtosecond laser line-by-line scanning method. A third-order obtained in single crystal with diameter of 60 μm. Compared to the SFBG written point-by-point method, method has higher reflectivity and about 15% achieved when track length 40 The temperature sensing characteristics from room 1600 °C are studied, sensitivity 34.96 pm/°C 1000 °C. strain also tested at 26 °C, 500 sensitivities 1.42, 1.44, 1.45 pm/με,...
A small-period long-period grating (LPG) with a period of 40μm fabricated in single-mode fiber by femtosecond laser direct writing has been demonstrated. series highorder Bragg resonant peaks and attenuation bands LPG can be observed simultaneously the broadband spectrum range that exhibited different responses to surrounding refractive index, temperature, axial strain. Meanwhile, we provided sensitivity matrix correct errors caused temperature measurements index strain achieve...
This paper reports the fabrication of parallel integrated sapphire fiber Bragg gratings (SFBGs) probe sensor by femtosecond laser point (PbP) method. The SFBGs transmits optical signals through quartz multimode fiber, and takes an 8.5 mm as sensing probe, which can work stably for a long time at 1200 °C. method not only quickly prepare obtain with small bandwidth, but also high reflectivity, is about 15%. mode field distribution in fibers different lengths studied beam quality analyzer....
An optically pumped AlGaN-based vertical-cavity surface-emitting laser (VCSEL) in the deep ultraviolet (DUV) range (<; 280 nm) is demonstrated. The lasing wavelength 275.91 nm with a threshold power density of 1.21 MW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and linewidth 0.78 nm. believed to be benefited from high internal quantum efficiency (IQE) multiple wells (MQWs) improved fabrication processes.
Magnetoresistance of modulation-doped ${\mathrm{Al}}_{0.22}{\mathrm{Ga}}_{0.78}\mathrm{N}/\mathrm{G}\mathrm{a}\mathrm{N}$ heterostructures has been studied by means magnetotransport measurements at low temperatures and high magnetic fields. The double periodicity the Shubnikov--de Haas oscillations was observed. It found that occupation first two subbands two-dimensional electron gas (2DEG) in triangular quantum well heterointerface took place when 2DEG sheet concentration reached...
In this paper, an energy regulation method based on the combination of a half-wave plate (HWP) and polarization beam splitter (PBS) is proposed for fabrication apodized fiber gratings, which can effectively improve side lobe suppression ratio high-reflectivity Bragg gratings (FBGs) fabricated by femtosecond laser. The FBGs prepared has good repeatability flexibility. By inputting different types apodization functions through program, rotation speed stepping motor be adjusted synchronously,...
Gallium Nitride (GaN)-based vertical-cavity surface-emitting lasers (VCSELs) in green spectral region face the difficulty of "green gap". One main obstacles is strong polarization electric field GaN-based materials, which leads to a quantum confinement Stark effect (QCSE) and reduces efficiency radiative recombination. In this study, we systemically simulated compared optical electrical performance VCSELs based on Ga-polar N-polar InGaN wells (QWs) by using software PICS3D. The results show...
Scanned reactive-ion-beam etching method was proposed to transfer two-dimensional mask patterns into quartz substrate, which would produce a larger-size and polarization-independent grating. This realized by moving grating substrate in unidimensional scanning manner adjusting ion beam density the vertical direction. Graphite plates between source were used correct density. The original Gaussian changed uniform distribution establish knife-edge shape around Therefore, large-area pattern with...
Magnetointersubband scattering (MIS) oscillations of two-dimensional electron gas (2DEG) in Al0.22Ga0.78N/GaN heterostructures have been investigated by means magnetotransport measurements at low temperatures and high magnetic fields. Double periodic Shubnikov–de Haas modulated MIS observed due to the intersubband 2DEG two lowest subbands triangular quantum well heterointerface. By using fast Fourier transform analysis, it is found that become slightly weaker with an increase temperature....
Optically pumped wavelength-tunable vertical-cavity surface-emitting lasers (VCSELs) operating in the ultraviolet A (UVA) spectrum were demonstrated. The VCSELs feature double dielectric distributed brag reflectors and a wedge-shaped cavity fabricated using substrate transfer technique laser lift off, resulting graded length one device. resonant period gain structure is used InGaN/GaN multi-quantum well active region to enhance coupling between mode field layers. optical inside modulated by...
The effect of the deposition temperature buffer layer In2S3 on band alignment CZTS/In2S3 heterostructures and solar cell performance have been investigated. films are prepared by thermal evaporation method at temperatures 30, 100, 150, 200 °C, respectively. By using x-ray photoelectron spectroscopy (XPS), valence offsets (VBO) determined to be , eV for deposited respectively, corresponding conduction (CBO) found eV, XPS study also reveals that inter-diffusion In Cu occurs interface...
A novel intensity-modulated directional torsion sensor based on a helical taper is proposed and experimentally demonstrated. The tapers are fabricated in standard single-mode fiber by electric-arc discharge, rotating one side simultaneously. Experimental results show that the intensity of transmission peak changes inversely when twisted clockwise counterclockwise, respectively. maximum sensitivity can reach -0.484 dB/(rad/m) twist rate ranges from -10.67 rad/m to 0 rad/m. Additionally, this...
Magnetotransport properties of modulation-doped Al0.22Ga0.78N/GaN heterostructures with different barrier thicknesses 25–100 nm have been investigated in magnetic fields up to 9 T at 1.4 K. Fast Fourier transform has applied obtain the subband density and mobility two-dimensional electron gas these heterostructures. High 1.18×1013 cm−2 quantum ∼8200 cm2 V−1 s−1 are obtained when thickness is 75 nm, which indicates that there exists a critical between 50 100 We also find elastic strain...
We report a method of using neodymium complexes as active waveguide core materials to achieve optical gain at the 1060 nm wavelength when an LED instead 808 semiconductor laser pump source. Through intramolecular energy transfer mechanism between ligands and Nd 3+ ions, photoluminescence spectrum could be obtained on 100µm thick film complex doped PMMA polymer under excitation 380 nm-450 LED. also present calculations showing that power required generate (turn-on power) for is 3.3 mW 40 mW,...
Multisubband transport of the two-dimensional electron gas (2DEG) in modulation-doped Al0.22Ga0.78N/GaN heterostructures has been investigated by means magnetotransport measurements at low temperatures and high magnetic fields. It is found that mobility 2DEG first subband a triangular quantum well heterointerface decreases significantly, while second increases, when Al0.22Ga0.78N barrier partially relaxed. Such behavior explained nonuniformity piezoelectric polarization field induced...
Magnetotransport properties of modulation-doped Al0.22Ga0.78N/GaN heterostructures were investigated by means magnetoresistance measurements at low temperatures and high magnetic fields. Strong Shubnikov–de Haas oscillations with the double periodicity are observed. The mobility spectrum is obtained, which demonstrates that mobilities two-dimensional electron gas (2DEG) in two subbands triangular quantum well heterointerface. It found 2DEG second subband much higher than first one. This...
In this paper, a sapphire-derived fiber (SDF) with core diameter of 10 μm and cladding 125 is fabricated by the melt-in-tube method, Bragg gratings (FBGs) reflectivity over 80% are prepared femtosecond laser point-by-point direct writing method. By analyzing refractive index distribution reflection spectral characteristics SDF, it can be seen that SDF graded few-mode fiber. order to study element composition core, end-face analyzed, which indicates diffusion occurred between materials. The...