Citation: | Dong Lizhi, Xu Bing, Yang Ping, et al. Recent progress of adaptive beam cleanup of solid-state slab lasers in Institute of Optics and Electronics, Chinese Academy of Sciences[J]. Opto-Electronic Engineering, 2018, 45(3): 170539. doi: 10.12086/oee.2018.170539 |
[1] | 李晋闽.高平均功率全固态激光器发展现状、趋势及应用[J].激光与光电子学进展, 2008, 45(7): 16-29. Li J M. Development, trend and application of high average power diode pumped lasers[J]. Laser & Optoelectronics Progress, 2008, 45(7): 16-29. |
[2] | 周寿桓, 赵鸿, 唐小军.高平均功率全固态激光器[J].中国激光, 2009, 36(7): 1605-1618. Zhou S H, Zhao H, Tang X J. High average power laser diode pumped solid-state laser[J]. Chinese Journal of Lasers, 2009, 36(7): 1605-1618. |
[3] | 彭钦军, 许祖彦.高平均功率固体激光功率和光束质量关系研究进展[J].强激光与粒子束, 2011, 23(7): 1707-1712. Peng Q J, Xu Z Y. Relationship between beam quality and power for solid state laser with high average power[J]. High Power Lasers and Particle Beams, 2011, 23(7): 1707-1712. |
[4] | Martin W S, Chernoch J P. Multiple internal reflection face-pumped laser: U. S. Patent 3633126[P]. 1972-01-04. |
[5] |
Machan J P, Long W H, Jr Zamel J, et al. 5. 4 kW diode-pumped, 2. 4x diffraction-limited Nd: YAG laser for material processing[C]//Advanced Solid State Laser 2002, 2002. |
[6] | Nishikawa Y. Slab-shaped 10-kW all-solid-state laser[J]. The Review of Laser Engineering, 2003, 31(8): 513-518. doi: 10.2184/lsj.31.513 |
[7] |
Redmond S, McNaught S, Zamel J, et al. 15 kW near-diffraction-limited single-frequency Nd: YAG laser[C]// Proceedings of Conference on Lasers and Electro-Optics, 2007. |
[8] | Textron defense systems achieves more than 100 kilowatts with J-HPSSL high-power laser[EB/OL]. (2010-02-18). http://www.defense-aerospace.com/articles-view/release/3/112461/textron-laser-achieves-over-100-kilowatts.html. |
[9] | Klimek D E, Mandl A. Nd: YAG ceramic ThinZag® high-power laser development[M]//Injeyan H, Goodno G D. High-Power Laser Handbook. New York: McGraw-Hill, 2011. |
[10] | 王超, 唐晓军, 徐鎏婧, 等.输出功率11 kW的高功率固体板条激光器介质热分析[J].中国激光, 2010, 37(11): 2807-2809. Wang C, Tang X J, Xu L J, et al. Investigation on thermal effect of high power slab laser with 11 kW[J]. Chinese Journal of Lasers, 2010, 37(11): 2807-2809. |
[11] | Chen Z Z, Xu Y T, Guo Y D, et al. 8.2 kW high beam quality quasi-continuous-wave face-pumped Nd:YAG slab amplifier[J]. Applied Optics, 2015, 54(16): 5011-5015. doi: 10.1364/AO.54.005011 |
[12] | Fan Z W, Qiu J S, Kang Z J, et al. High beam quality 5 J, 200 Hz Nd:YAG laser system[J]. Light: Science & Applications, 2017, 6: e17004. |
[13] | Tang B, Zhou T J, Wang D, et al. Optical distortions in end-pumped zigzag slab lasers[J]. Applied Optics, 2015, 54(10): 2693-2702. doi: 10.1364/AO.54.002693 |
[14] | Yu X, Dong L Z, Lai B H, et al. Adaptive aberration correction of a 5 J/6.6 ns/200 Hz solid-state Nd:YAG laser[J]. Optics Letters, 2017, 42(14): 2730-2733. doi: 10.1364/OL.42.002730 |
[15] | Yu X, Dong L Z, Lai B H, et al. Automatic low-order aberration correction based on geometrical optics for slab lasers[J]. Applied Optics, 2017, 56(6): 1730-1739. doi: 10.1364/AO.56.001730 |
[16] | Jiang W H, Li H G. Hartmann-shack wavefront sensing and wavefront control algorithm[J]. Proceedings of SPIE, 1990, 1271: 82-93. doi: 10.1117/12.20396 |
[17] | Chen S Q, Dong L Z, Chen X J, et al. Adaptive slab laser beam quality improvement using a weighted least-squares reconstruction algorithm[J]. Applied Optics, 2016, 55(11): 3077-3083. doi: 10.1364/AO.55.003077 |
[18] | Chen S Q, Zhao E Y, Xu B, et al. A compact Multi-core CPU based adaptive optics real-time controller[J]. Proceedings of SPIE, 2014, 9280: 928012. doi: 10.1117/12.2068322 |
[19] | 王喆, 刘洋, 刘磊, 等. LD侧泵Nd:YAG薄板条MOPA激光器[J].激光与红外, 2015, 45(4): 364-368. Wang Z, Liu Y, Liu L, et al. Laser diode side-pumped Nd:YAG thin slab laser based on MOPA[J]. Laser & Infrared, 2015, 45(4): 364-368. |
[20] | Dong L Z, Chen S Q, Chen X J, et al. Adaptive compensation of a direct liquid-cooled solid-state MOPA system[J]. Proceedings of SPIE, 2015, 9982: 99820H. |
[21] | 谭毅, 杨平, 董理治, 等. 基于59单元自适应光学系统的脉冲板条固体激光光束净化研究[J]. 中国科学: 物理学力学 天文学, 2017, 47(8): 084207. Tan Y, Yang P, Dong L Z, et al. Active beam cleanup of pulsed slab laser based on 59-unit adaptive optics system[J]. Scientia Sinica Physica, Mechanica & Astronomica, 2017, 47(8): 084207. |
Overview: The solid-state slab laser is a promising architecture for power scaling. However, the beam qualities of high power solid-state slab lasers are severely limited by many factors such as thermal effects of the gain medium. Simultaneously achieving high beam quality and high average output power remains a fundamental problem in the development of high power solid-state slab lasers. Adaptive optics systems are able to significantly improve beam qualities by compensating for both static and dynamic phase distortions of the beams. Compared to adaptive optics systems for other types of laser systems, solid-state slab lasers specifically demand large-amplitude low-order aberration compensations of laser beams with high aspect ratio, advanced manipulations of large local phase gradients, and extra flexible real-time wavefront controllers. In recent years, Institute of Optics and Electronics, Chinese Academy of Sciences has successfully developed low-order aberration compensators based on geometric optics, weighted least-square wavefront reconstruction algorithms, and generic real-time wavefront processors implemented with x86 CPUs and real-time operating systems. Based on these state of the art techniques and components, we have developed several types of hybrid adaptive optical system for solid-state slab laser systems, which contains low-order aberration compensators based on several cylindrical and spherical lenses mounted on a motorized rail, and uncooled piezo electric deformable mirror adaptive optical systems. We have offered an adaptive optics system to a 5 J/6.6 ns/200 Hz Nd:YAG solid-state slab laser system developed by Academy of Opto-electronics, Chinese Academy of Sciences, and achieved beam quality of β=1.64 after correction. We have also developed adaptive optics systems for a continuous wave Nd:YAG conduction-cooled, end-pumped slab laser systems of the No.11 Institute, China Electronics Technology Group Corporation. After Correction, the beam quality was improved to β=2.0. To guarantee high beam quality of the quasi-continuous wave Nd:YAG direct liquid cooled slab laser, we integrated an adaptive optics system into the laser system, and beam quality of β=1.7 was achieved. Besides, we have also developed adaptive optics systems for many different solid-state slab laser systems, and significant beam quality improvements were obtained. In the past decade, Institute of Optics and Electronics, Chinese Academy of Sciences have delivered over two dozens of adaptive optics systems for beam cleanup. With effective operations of these adaptive optics systems, the beam qualities of the laser systems have all been well improved. We will continue to develop adaptive optics for various types of laser systems in the future.
Schematic of the low-order aberration compensator designed for the high-power nanosecond laser system developed by Academy of Opto-electronics, Chinese Academy of Sciences[14]. (a) Zigzag direction; (b) Non-zigzag direction
Software interface of the generic real-time wavefront processor
The hybrid adaptive optics system developed for the 5 J/6.6 ns/200 Hz slab laser system
The 59-actuator piezo electric deformable mirror used in the hybrid adaptive optic system
Results of beam cleanup of the 5 J/6.6 ns/200 Hz Nd:YAG slab laser system. (a) Initial Intensity distribution of the output beam, the approximate size of the beam is 7 mm×35 mm; (b) Initial wavefront of the output beam, PV=26.47 μm, RMS=6.12 μm; (c) Wavefront after corrected by the low-order aberration compensator, PV=1.91 μm, RMS=0.29 μm; (d) Residual wavefront after corrected by the 59-actuator deformable mirror, PV=0.45 µm, RMS=0.09 µm; (e) Intensity distribution of the beam after compensated by the low-order aberration compensator, the approximate size of the beam is 42 mm×44 mm; (f) Far-field intensity distribution of the initial beam, β=18.42; (g) Far-field intensity distribution of the beam after corrected by the low-order aberration compensator, β=2.86; (h) Far-field intensity distribution of the beam after corrected by the 59-actuator deformable mirror, β=1.64.
Wavefront of the output beam from the kW-class CCEPS laser system after low-order aberration compensation
Results of beam cleanup of a CW CCEPS Nd:YAG slab laser system[17]. (a) Far-field intensity distribution of the output beam after corrected by the low-order aberration corrector; (b) Far-filed intensity distribution of the beam after correction by the deformable mirror based on the conventional least-square wavefront reconstruction method, β=2.5; (c) Far-filed intensity distribution of the beam after correction by the deformable mirror based on the weighted least-square wavefront reconstruction method, β=2.0
Results of beam cleanup of a kW-class QCW direct liquid-cooled Nd:YAG slab laser system developed by CETC 11[20]. (a) Intensity distribution of the output beam after corrected by the low-order aberration corrector; (b) Far-filed intensity distribution of the beam after corrected by the low-order aberration corrector; (c) Far-filed intensity distribution of the beam after corrected by the deformable mirror, β=1.7