A5101590375- Semiconductor Lasers and Optical Devices
- Photonic and Optical Devices
- Semiconductor Quantum Structures and Devices
- Stochastic processes and statistical mechanics
- Stochastic processes and financial applications
- Optical Systems and Laser Technology
- Gas Dynamics and Kinetic Theory
- Markov Chains and Monte Carlo Methods
- Quantum chaos and dynamical systems
- Laser Material Processing Techniques
- Random Matrices and Applications
- Solid State Laser Technologies
- Topological and Geometric Data Analysis
- Adhesion, Friction, and Surface Interactions
- Advanced Optical Sensing Technologies
- Advanced optical system design
- Mathematical Biology Tumor Growth
- Ocular and Laser Science Research
- Theoretical and Computational Physics
- Higher Education and Teaching Methods
- Advanced Thermodynamics and Statistical Mechanics
- Data Management and Algorithms
- Navier-Stokes equation solutions
- Medical Image Segmentation Techniques
- Advanced Fiber Laser Technologies
Xi'an Institute of Optics and Precision Mechanics
2012-2024
Peking University
2023
Peking University International Hospital
2023
Chinese Academy of Sciences
2008-2021
University of Pennsylvania
2019-2020
University of Maryland, College Park
2017-2018
State Key Laboratory of Transient Optics and Photonics
2012-2013
Changchun Institute of Optics, Fine Mechanics and Physics
2008-2011
University of Chinese Academy of Sciences
2009-2011
Daqing Normal University
2010-2011
The reliability of packaged laser diodes is heavily dependent on the quality die attach. Even a small void or delamination may result in sudden increase junction temperature, eventually leading to failure operation. contact thermal resistance at interface between attach and heat sink plays critical role management high-power diode packages. This paper focuses investigation using transient analysis. structure function flow path T3ster testing experiment utilized. By analyzing characteristics,...
Abstract Laser Power Transmission (LPT) is emerging as a highly promising method for wireless energy transfer, particularly extending the operational endurance of small unmanned aerial vehicles (UAVs) and supporting construction space-based solar power stations. This study investigated optimal parameters single-junction gallium arsenide
(GaAs) photovoltaic (PV) cells under laser diode (LD) irradiation to enhance efficiency of
LPT systems. A detailed theoretical analysis was...
Abstract We consider the asymptotic behaviour of fluctuations for empirical measures interacting particle systems with singular kernels. prove that sequence fluctuation processes converges in distribution to a generalized Ornstein–Uhlenbeck process. Our result considerably extends classical results kernels, including Biot–Savart law. The applies point vortex model approximating 2D incompressible Navier–Stokes equation and Euler equation. also obtain Gaussianity optimal regularity limiting...
Vertical-cavity surface-emitting lasers emitting at 808 nm with unstrained GaAs/Al0.3Ga0.7As, tensilely strained GaAs(x)P(1-x)/Al0.3Ga0.7As and compressively In(1-x-y)Ga(x)Al(y)As/Al0.3Ga0.7As quantum-well active regions have been investigated. A comprehensive model is presented to determine the composition width of these quantum wells. The numerical simulation shows that gain peak wavelength near 800 room temperature for GaAs well 4 nm, GaAs0.87P0.13 13 In0.14Ga0.74Al0.12As 6 nm....
High power and good beam quality of two-dimensional bottom-emitting vertical-cavity surface-emitting laser array with GaAs microlens on the substrate is achieved. Uniform matched convex directly fabricated by one-step diffusion-limited wet-etching techniques emitting windows. The maximum output above 1 W at continuous-wave operation room temperature, far-field divergence below 6.6° a current 4 A. These properties between microlens-integrated conventional device different operating are demonstrated.
We report on the development of a 940-nm diode laser bar based epitaxially stacked active regions by employing tunnel junction structure. The and device parameters were systematically optimized to achieve high output power conversion efficiency. A record quasi-continuous wave (QCW) peak 1.91 kW at 25 °C was demonstrated from 1-cm wide with 2-mm cavity length 1 kA drive current (200 μs pulse width 10 Hz repetition rate). Below onset thermal rollover, slope efficiency as 2.23 W/A. maximum...
The package structure critically influences the major characteristics of semiconductor lasers, such as thermal behavior, output power, wavelength, and far-field distribution. In this paper, a new single emitter called F-mount is designed compared with conventional C-mount. influence on their performances characterized analyzed. resistances lasers different structures are calculated through simulation, contrasted experimental results. Some devices also tested for maximum power level. Under...
A new beam-shaping technique is proposed to improve the beam quality of a high-power diode laser area light source. It consists two staggered prism arrays and reflector array, which can cut slow axis twice rearrange divided beams in fast make both axes approximately equal. Furthermore, transformation compression be carried out simultaneously, assembly error this induced by machining accuracy prism's dimensions also greatly decreased. By technique, fiber-coupled system for one three-bar stack...
A 980 nm bottom-emitting vertical-cavity surface-emitting laser (VCSEL) with a p-contact diameter is reported to achieve high power and good beam quality. numerical simulation conducted on the current spreading in VCSEL oxidation between active region p-type distributed Bragg reflector. It found that, for particular oxide aperture diameter, somewhat homogeneous distribution can be achieved an optimized diameter. The far-field divergence angle from 600 microm suppressed 30 degrees 15 degrees,...
With the continuous increase of output power semiconductor laser array, heat generation in active region also increases continuously, which influences performances and lifetime array seriously. In order to improve lifetime, understanding thermal behavior high packages optimizing performance are crucial. By means numerical analysis, a three-dimensional model has been established, static transient characteristics continuous-wave (CW) quasi-continuous-wave (QCW) modes have studied...
We prove the uniqueness of weak solutions to spatially homogeneous special relativistic Landau equation under conditional assumption that solution satisfies $(p^0)^7 F(t,p) \in L^1 ([0,T]; L^\infty)$. The existence standard has been shown recently in (arXiv:1806.08720)
Thermomechanical behavior has an important effect on reliability and lifetime of high-power diode lasers (HPDLs). Finite-element analysis (FEA) model analytical solution the conduction-cooled package (CS) HPDL are established to analyze thermomechanical including normal stress, shearing displacement in reflowing process working process. Moreover, order simulate total process, thermal stress considered as residual initial condition We find that is origin other due coefficient expansion (CTE)...
The 808 nm high-efficiency laser diodes have many advantages, such as high output power, reliabilities, compact sizes, which are widely used in areas, industry, communication, science, medicine and biology. In order to improve the power conversion efficiencies of diodes, following requirements must be considered, loss joule heating, by carrier leakage, spontaneous radiation below threshold current, interface voltage defect, internal losses including free-carrier absorption scattering loss....
This is the document corresponding to talk first author gave at IHÉS for Laurent Schwartz seminar on November 19, 2019. It concerns our recent introduction of a modulated free energy in mean-field theory [4]. physical object may be seen as combination potential introduced by S. Serfaty [See Proc. Int. Cong. Math. (2018)] and relative entropy mean field limit P.–E. Jabin, Z. Wang Inventiones 2018]. allows obtain, time, convergence rate Riesz Coulomb repulsive kernels presence viscosity using...
We derive the spatially homogeneous Landau equation for Maxwellian molecules from a natural stochastic interacting particle system. More precisely, we control relative entropy between joint law of system and tensorized equation. To obtain this, establish as key tools pointwise logarithmic gradient Hessian estimates density function also new Law Large Numbers result The are derived via Bernstein method parabolic maximum principle, while comes crucial observations on moments at level.