A5101845479- Spectroscopy and Laser Applications
- Metamaterials and Metasurfaces Applications
- Plasmonic and Surface Plasmon Research
- Photonic Crystals and Applications
- GaN-based semiconductor devices and materials
- Semiconductor Lasers and Optical Devices
- Photonic and Optical Devices
- Strong Light-Matter Interactions
- Photocathodes and Microchannel Plates
- ZnO doping and properties
- Ga2O3 and related materials
- Advanced Optical Sensing Technologies
- Optical Coatings and Gratings
- Housing Market and Economics
- Seismic Performance and Analysis
- Terahertz technology and applications
- Financial Markets and Investment Strategies
- Spectroscopy and Chemometric Analyses
- Spectroscopy Techniques in Biomedical and Chemical Research
- Gas Sensing Nanomaterials and Sensors
- Advanced Fluorescence Microscopy Techniques
- Fusion materials and technologies
- Plant Molecular Biology Research
- Light effects on plants
- Ocular and Laser Science Research
University of California, Los Angeles
2020-2024
South China Normal University
2015-2024
University of California System
2021
Polar Research Institute of China
2021
University of Shanghai for Science and Technology
2020
Shanghai University
2012-2018
Massachusetts Institute of Technology
2017
Tsinghua University
2005-2016
China University of Petroleum, East China
2012
Shanghai Institute of Microsystem and Information Technology
2008
Abstract Engineered microsphere possesses the advantage of strong light manipulation at sub-wavelength scale and emerges as a promising candidate to shrink focal spot size. Here we demonstrated center-covered engineered which can adjust transverse component incident beam achieve sharp photonic nanojet. Modification width working distance nanojet were achieved by tuning cover ratio microsphere, leading size exceeded optical diffraction limit. At wavelength 633 nm, 245 nm (0.387 λ) was...
Abstract The development of novel approaches that control absorption and emission operating in the long wavelength infrared (LWIR) spectral region is fundamental importance for many applications, such as remote temperature sensing, thermal imaging, radiation cooling, environmental monitoring, night vision. A high performance plasmonic metasurface–based absorber LWIR presented. In design, a pyroelectric thin film, poly(vinylidene fluoride‐trifluoroethylene) (P(VDF‐TrFE)) copolymer, introduced...
Purpose This study investigates whether there was a housing price bubble in Beijing and Shanghai 2003. The existence of can be interpreted from (abnormal) interactions between prices market fundamentals. Design/methodology/approach With monthly data the two cities, this paper employs standard econometric methodologies: i.e. Granger causality tests generalized impulse response analysis, reduced form determinants. Findings Our findings suggest that appeared 2003, accounting for 22 percent...
We report a terahertz quantum-cascade vertical-external-cavity surface-emitting laser (QC-VECSEL) emitting around 1.9 THz with up to 10% continuous fractional frequency tuning of single mode. The device shows lasing operation in pulsed mode 102 K high-quality beam, the maximum output power 37 mW and slope efficiency 295 mW/A at 77 K. Challenges for up-scaling operating wavelength QC metasurface VECSELs are identified.
An amplifying quantum-cascade (QC) metasurface, the key component of QC vertical-external-cavity surface-emitting-laser (VECSEL), is studied as a function injected current density using reflection-mode terahertz time domain spectroscopy. Nearly perfect absorption measured at zero bias, which associated with transition from weak to strong coupling condition between metasurface resonance and an intersubband within material. increase in reflectance observed device biased, both due reduction...
This paper presents an investigation of the interaction between housing prices and general economic conditions in China for period 1986–2002. The empirical results indicate that are predictable by market fundamentals, which could explain most variations prices. Granger causality tests confirm unemployment rate, total population, changes construction costs, consumer price index (CPI) all causalities prices, with feedback effects observed to affect vacancy rate new dwellings, CPI, per capita...
A novel five-period AlGaN/AlGaN multiple quantum wells light-emitting diodes (LEDs) structure with Al content graded AlGaN barriers is designed in order to improve the electrical and optical performance of ultraviolet LEDs (UV-LEDs), effects are analyzed by using APSYS simulation programs. The results show that effective potential height for electrons increased, simultaneously holes decreased increased number barriers, which contributes less electron leakage better hole injection efficiency....
There is currently considerable interest in developing electro-optic systems for underwater imaging classification and identification of submerged objects such as fish shoals mines. The can be divided into active passive systems. main feature the that they haven’t illumination sources depend on lights from targets or surroundings. use light to illuminate collect reflection targets. advantages over are high contrast without affection environment sources. gated Intensified CCD (ICCD) cameras...
When light passes through an interface between two media with different refractive indices, part of energy is reflected and thus causes inevitable optical reflection. Optical anti-reflection great importance for applications in a wide range such as solar cells, lenses, infrared sensors, photo-detectors, which has long been research topic the fields systems optoelectronic devices. In this article, recent progress based on subwavelength artificial engineering materials reviewed. Having made...
A theoretical study of polar and semi/non-polar InGaN/GaN light-emitting diodes (LEDs) with different internal surface polarization charges, which can be grown on Si substrates, is conducted by using APSYS software. In comparison structure LEDs, the semi-polar exhibits a higher concentration electrons holes radiative recombination rate, its reduced built-in field weakens extent band bending causes shift peak emission wavelength. So efficiency droop LEDs declines obviously optical power...
The authors report the formation of air void arrays with controlled size and density embedded in GaN epitaxial layers by patterning re-growth. It was found that wizard’s-hat-shaped voids were formed after coalescence. GaN-based light-emitting diodes (LEDs) such also fabricated to achieve a 56% enhancement LED output power embedding 3 μm × due effective scattering re-direction photons emitted from active region LEDs.
ABSTRACT Carnosic acid (CA) is recognized as an antioxidant that confers protection to plants against various forms of oxidative stress, including UV‐B stress. However, limited research has been conducted elucidate the molecular mechanisms underlying its defence In this study, we demonstrated CA exhibits more efficacy compared other antioxidants in resistance. Moreover, was found enhance accumulation secondary metabolites Arabidopsis leaves. Through analysis differentially expressed genes...
A model is currently being developed for simulating images of underwater objects as seen by airborne laser range-gated (LRG) system. The simulation based on physically accurate models wind generated waves the sea surface, and optical properties ocean water. It can take input any digital image simulate its degradation due to scattering in water through wavy surface. This paper describes implementation LRG system presents results simulations. Simulation presented here allow visual evaluation...
Coherent anti-Stokes Raman scattering (CARS) can be used to excite vibrational bonds with chemical selectivity, high spatial and spectral resolution, sensitivity, which has many applications in biomedical research. The common way realize CARS imaging is illuminating sample two synchronized ultra-short pulses. Recent development of various fiber laser schemes based on nonlinear optical effect provides compact source for imaging. However, the conversion may inevitably introduce temporal or...
We report advances in the development of THz quantum-cascade metasurface VECSELs intended for use as local oscillators terahertz heterodyne receiver instruments astrophysical investigation interstellar medium. First, by using a patch-based amplifying we obtain QC-VECSEL lasing with milliwatt output power at 4.6 reduced consumption less than 1 W. Second, phase locking 3.4 to microwave reference Schottky diode mixer. Finally, efforts and challenges scale down frequency 1.9 THz.
The emission of light from electrons passing near a grating includes resonant plasmonic features and Smith-Purcell collective excitations. We observe both distinguish between them, finding surprising robustness to disorder in the radiation.
We present direct measurements using reflection-mode terahertz (THz) time domain spectroscopy (TDS) of amplifying quantum-cascade (QC) metasurfaces used in THz QC-VECSELs. Devices resonant at 2.2 and 2.5 are studied under different bias currents, exhibit gain-induced partial compensation losses.
An amplifying quantum-cascade (QC) metasurface – the key component of QC vertical-external-cavity surface-emitting-laser (VECSEL) is studied as a function current density using reflection-mode terahertz time domain spectroscopy. Nearly perfect absorption and an anomalous reflection phase characteristic measured at zero bias, which disappears device biased to provide gain. This attributed critical coupling between lossy intersubband transition within active material resonance. These results...
Objective In polar regions, the operation mode of launching and recovering detection sampling devices for scientific research by shipside is limited due to dense ice floes around ship. For achieving smooth acquisition data records samples in densely packed a square shape moonpool system was designed mid-ship Xuelong 2 icebreaker. Methods Benefiting from accumulated experiences surveys decades, taking into full account characteristics zone, design option reasonable setting switching process...