Proceedings Article | 6 December 2011
Wen-bin Qin, You-qiang Liu, Yin-hua Cao, Jing Gao, Fei Pan, Zhi-yong Wang
KEYWORDS: Semiconductor lasers, Beam shaping, Collimation, Materials processing, Optical simulations, Metals, Laser welding, Cladding, Laser processing, High power lasers
This article describes high beam quality and kilowatt-class diode laser system for direct materials processing, using
optical design software ZEMAX® to simulate the diode laser optical path, including the beam shaping, collimation,
coupling, focus, etc.. In the experiment, the diode laser stack of 808nm and the diode laser stack of 915nm were used
for the wavelength coupling, which were built vertical stacks up to 16 bars. The threshold current of the stack is 6.4A,
the operating current is 85A and the output power is 1280W. Through experiments, after collimating the diode laser
beam with micro-lenses, the fast axis BPP of the stack is less than 60mm·mrad, and the slow-axis BPP of the stack is
less than 75mm·mrad. After shaping the laser beam and improving the beam quality, the fast axis BPP of the stack is
still 60mm·mrad, and the slow-axis BPP of the stack is less than 19mm·mrad. After wavelength coupling and focusing,
ultimately the power of 2150W was obtained, focal spot size of 1.5mm * 1.2mm with focal length 300mm. The laser
power density is 1.2×105W/cm2, and that can be used for metal remelting, alloying, cladding and welding. The total
optical coupling conversion efficiency is 84%, and the total electrical - optical conversion efficiency is 50%.
