- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2019 Chinese Control And Decision Conference (CCDC) - Nanchang, China (2019.6.3-2019.6.5)] 2019 Chinese Control And Decision Conference (CCDC) - Design of an Intelligent Temperature Control System for High-power LED Lighting
摘要： An intelligent temperature control system for high-power LED (Light-Emitting Diode) lighting has been designed in this paper. The system includes single-chip microcomputer STC12C5412, temperature sensor module DS18B20, power module, LED circuit driver module, LED air-cooled cooling driver module and Bluetooth module. The temperature sensor module collects data and drives the LED air cooling system through a single chip microcomputer. The Bluetooth module is used to receive wireless signal and transmit the signal to the single chip microcomputer. The microcontroller closes the air cooling system by outputting PWM (Pulse Width Modulation) signal and controls the LED driving circuit to reduce the driving current at the same time. As a result, the junction temperature of LED decreased. The Bluetooth module can also support the expansion of lighting effects such as color conversion.
关键词： Bluetooth,Intelligent system,High-power LED,Temperature control
更新于2025-09-12 10:27:22
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Weld pool shape observation in high power laser beam welding
摘要： The geometry of the melt pool in laser beam welding plays a major role to understand the dynamics of the melt and its solidification behavior. In this study, a butt configuration of 15 mm thick structural steel and transparent quartz glass was used to observe the weld pool geometry by means of high-speed camera and an infrared camera recording. The observations show that the dimensions of the weld pool vary depending on the depth. The areas close to the weld pool surface take a teardrop-shape. A bulge-region and its temporal evolution were observed approximately in the middle of the depth of the weld pool. Additionally, a 3D transient thermal-fluid numerical simulation was performed to obtain the weld pool shape and to understand the formation mechanism of the observed bulging effect. The model takes into account the local temperature field, the effects of phase transition, thermo-capillary convection, natural convection and temperature-dependent material properties up to evaporation temperature. The numerical results showed good accordance and were furthermore used to improve the understanding of the experimentally observed bulging effect.
关键词： high power laser beam welding,transient weld pool shape,bulging,numerical process simulation
更新于2025-09-12 10:27:22
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Efficient micro processing with high power femtosecond lasers by beam engineering and modelling
摘要： Hybrid femtosecond lasers today deliver output powers of several hundred watts. Translating the available power into high-speed micromachining requires new approaches such as beam delivering tools with suitable synchronization of the laser pulses. We study the interest of rapid scanning systems or multi-beam shaping but also a rapid estimation of the ablation efficiency using a simple engineering model.
关键词： femtosecond processing,femtosecond ablation modelling,high power ultra fast lasers,beam shaping
更新于2025-09-12 10:27:22
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High Power Pulse Laser Reflection Sequence Combination with a Fast Steering Mirror
摘要： We propose and demonstrate a new approach for a high power pulse laser reflection sequence combination with a fast steering mirror (FSM). This approach possesses significant advantages for lasers combining with a variety of output power, wavelength, pulse duration, repetition rates and polarization. The maximum number of laser routes participating in combination principally depends on the FSM’s adjustment time of the step response, lasers’ repetition rates and pulse duration. A proof-of-principle experiment is performed with two 2-kW level pulsed beams. The results indicate that the combined beam has an excellent pointing stability with rms pointing jitter ～8.5 ??rad. Meanwhile, a high combining efficiency of 98.6% is achieved with maintaining good beam quality.
关键词： combining efficiency,fast steering mirror,high power pulse laser,reflection sequence combination,pointing stability
更新于2025-09-12 10:27:22
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Surface treatments of forged steel AISI6F3 by using high power CO <sub/>2</sub> laser
摘要： The hardness of forging dies is highly affected by the hot forming processes; especially by the long exposure to a wide thermal range, which leads to a decline in the level of hardness due to the tempering of the microstructure, thus failure occurs and the die breaks. The microstructure and hardness have been studied to demonstrate the relationship between them and their direct effect on the regions generated by the laser treatment of high capacity. The selected samples were chosen within a combination of laser variables to reach the appropriate structure that achieves the best hardness and indeed the highest hardness value (965 Hv) with laser processing parameters included the power 3000 W, beam diameter 1mm and scanning speed 25 mm/s with its characteristic microstructure as well as its high cooling rate.
关键词： High power laser,Forged steel,Hardness,Microstructure
更新于2025-09-12 10:27:22
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High power GHz femtosecond laser for ablation efficiency increase
摘要： Nowadays the relevance and the robustness of ultrafast lasers are well established for many industrial applications. The main limitation to the penetration of femtosecond processing in the industrial manufacturing market is the insufficient productivity compared to the needs of the application markets and alternative technologies. Increasing the power, pulse energy or repetition rate, of femtosecond lasers has been a general trend in in order to comply to the needs of the market for higher throughput. One of the strategies of increasing the power has resulted in the development of a GHz femtosecond laser. When increasing the repetition rate during the process beyond several hundred kHz, the delay between the laser pulses is less than the thermal relaxation time and there is thermal accumulation in the target material. The resulting rise in temperature leads to an ablation threshold lowering. The authors report on a simple and easy-to-use GHz amplified femtosecond laser source. The laser source is based on a passively mode-locked oscillator with a near GHz repetition rate. GHz pulses are then selected, and the obtained bursts of pulses are further amplified in a high-power amplifier chain. The presented GHz femtosecond laser source is used with a galvanometric scanner to perform ablation experiments on copper, aluminum, and stainless steel. Specific ablation rates of 0.7, 2.3, and 1.4 (mm3/min)/W are reached. The role of the important experimental parameters, such as the number of sub-pulses in the burst, is highlighted. Thanks to a specific ablation scheme in the GHz mode, the ablation efficiency is then comparable to the case of single nanosecond pulses, but with the usual quality of femtosecond processing.
关键词： ultrashort pulse,efficiency,GHz,high power,ablation,Amplitude,laser,femtosecond
更新于2025-09-12 10:27:22
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Proton acceleration by collisionless shocks using a supersonic H <sub/>2</sub> gas-jet target and high-power infrared laser pulses
摘要： For most laser-driven ion acceleration applications, a well-characterized intense ion beam with a low divergence and a controllable energy spectrum produced at a high repetition rate is needed. Gas-jet targets have given promising results in simulations, and they have several technical advantages for high-repetition-rate lasers. In this work, we report on proton acceleration to energies up to 6 MeV using a supersonic H2 gas-jet target at the LULI PICO2000 laser facility. The experimental results are compared with the plasma hydrodynamics and the particle-in-cell simulations to identify the acceleration mechanisms at play.
关键词： supersonic H2 gas-jet target,collisionless shocks,proton acceleration,high-power infrared laser pulses
更新于2025-09-12 10:27:22
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Lasers for Novel Accelerators
摘要： Novel accelerator schemes are rapidly emerging in the wake of laser-plasma acceleration research and involve advanced high-power laser drivers for their operation. Significant progress has been made in laser performance during the past decade, including repetition rate, average and peak power, and footprint, making these systems attractive for many applications, including novel accelerators. Here we discuss laser driver requirements for the proposed novel accelerator schemes, examine emerging technologies and introduce a viable laser driver concept for a first generation of plasma accelerators.
关键词： novel accelerators,lasers,laser-plasma acceleration,high-power laser drivers
更新于2025-09-12 10:27:22
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High Power Quantum Cascade Laser at λ 5.1 <i>μ</i> m Based on Low Strain Compensation Design
摘要： We demonstrate the development of a high performance quantum cascade laser at (cid:2) ～ 5(cid:3)1 (cid:4)m with low strain-balanced structure using a double-phonon resonant design approach. The wafer was grown by solid source molecular beam epitaxy and fabricated with buried heterostructure waveguides. A high output power up to 1.5 W is obtained at 288 K with a high wall plug ef?ciency of 8.5% for devices with stripe dimension of 5 mm × 10 (cid:4)m. The characteristic temperatures, T 1, are 114 K and 198 K respectively.
关键词： High Power Laser,Strain-Compensation,Quantum Cascade Laser
更新于2025-09-12 10:27:22
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Model-based analysis of highly dynamic laser beam shaping using deformable mirrors
摘要： Deformable mirrors show large potential for the dynamic beam shaping in high power laser applications. A model which is based on influence functions is used to systematically investigate the beam shaping capabilities of several deformable mirrors based on the underlying technology and the number of actuators.
关键词： deformable mirror,dynamic beam shaping,high power,influence functions,piezoelectric mirror,membrane mirror
更新于2025-09-12 10:27:22