Author Affiliations
Abstract
1 National Key Laboratory of Science and Technology on Tunable Laser, Harbin Institute of Technology, Harbin 150001, China
2 Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China
A 100-J-level Nd:glass laser system in nanosecond-scale pulse width has been constructed to perform as a standard source of high-fluence-laser science experiments. The laser system, operating with typical pulse durations of 3–5 ns and beam diameter 60 mm, employs a sequence of successive rod amplifiers to achieve 100-J-level energy at 1053 nm at 3 ns. The frequency conversion can provide energy of 50-J level at 351 nm. In addition to the high stability of the energy output, the most valuable of the laser system is the high spatiotemporal beam quality of the output, which contains the uniform square pulse waveform, the uniform flat-top spatial fluence distribution and the uniform flat-top wavefront.
design design frequency conversion frequency conversion laser amplifiers laser amplifiers laser engineering laser engineering laser systems laser systems light propagation light propagation modeling modeling nonlinear optics nonlinear optics optimization optimization wavefront correction wavefront correction High Power Laser Science and Engineering
2016, 4(1): 01000e10
Author Affiliations
Abstract
National Key Laboratory of Science and Technology on Tunable Laser, Harbin Institute of Technology, Harbin 150080, China
The characteristics of stimulated Brillouin scattering (SBS) in perfluorinated amine media and the experimental structure used in hundreds of picoseconds pulse compression at 532 nm are demonstrated. A two-stage SBS pulse compression structure is adopted for this work. The compact double-cell SBS compression structure and the scattering media FC-70 are chosen to compress the incident light from 9.5 to about 1 ns in the first stage. Then, the light is used as the pumping source for the second pulse compression. In the second stage, using a single-cell SBS structure in a pulse compression system, perfluorinated amine media with different phonon lifetimes, such as FC-3283, FC-40, FC-43, and FC-70, are chosen to run the comparative experimental study. The narrowest compressed pulse times obtained are 294, 274, 277, and 194 ps; they respectively correspond to the above listed media. The average width of the compressed pulse width is 320 ps for FC-3283, with a fluctuation range of 87 ps. For FC-40, the average pulse width is 320 ps, with a fluctuation range of 72 ps. And for FC-43, the average pulse width is 335 ps, with a fluctuation range of 88 ps. However, the average pulse width is only 280 ps for FC-70, with a fluctuation range of 57 ps. The highest energy reflectivity is more than 80% for all of the media. The experimental results show that a two-stage SBS pulse compression system has lower pump energy requirements, thus making it easier to achieve a compressed pulse waveform. The results also show that the shorter the phonon lifetime of the medium, the narrower the obtained compressed pulse width.
190.0190 Nonlinear optics 140.0140 Lasers and laser optics Chinese Optics Letters
2015, 13(6): 061901
1 中国计量学院 光学与电子科技学院,浙江 杭州 310018
2 哈尔滨工业大学 光电子技术研究所,黑龙江 哈尔滨 150001
将波长1064 nm,脉冲宽度8 ns 的Nd:YAG 激光脉冲聚焦到FC-72 介质池中,利用CCD 对后向受激布里渊散射(SBS)光斑进行检测,并利用数字图像处理技术对图像进行分析,以获得SBS 光斑的空间光强分布和变化规律。利用MATLAB 的图像处理工具箱对激光光斑的原始CCD 图像进行去噪,并使用Origin 软件的曲线拟合和FFT 平滑功能对光强分布曲线进行平滑处理。结果表明,进行图像处理后的原图像噪声被有效地抑制和消除,光强分布曲线较为平滑。在入射光束为基模高斯光束的条件下,随着入射光能量增大,受激布里渊散射光斑的空间光强分布由近高斯型转变为高斯型。
检测 受激布里渊散射 光强分布 图像处理 激光与光电子学进展
2010, 47(5): 051201
1 哈尔滨工业大学可调谐激光技术国家级重点实验室, 黑龙江 哈尔滨 150001
2 中国原子能科学研究院, 北京 102413
对纳秒级宽带KrF激光脉冲的时间整形进行了研究。采用受激布里渊散射(SBS)脉冲压缩KrF激光获得短脉冲,通过脉冲堆积获得KrF激光时间整形脉冲。利用激光放大器对整形脉冲进行放大,对KrF激光整形脉冲的形状影响较大。通过对放大前整形脉冲形状的调整,在放大后可以得到所需形状的整形脉冲,一次放大能量输出可达50 mJ,二次放大能量输出可达300 mJ。理论分析与实验结果一致。研究表明,短脉冲堆积和放大器放大的组合方案具有较强的整形能力。
激光技术 KrF激光 脉冲整形 脉冲堆积 放大 宽带
1 哈尔滨工业大学光电子技术研究所, 黑龙江 哈尔滨 150001
2 中国计量学院光电子技术研究所, 浙江 杭州 310018
将调Q的Nd:YAG激光脉冲聚焦到FC-72介质池中,利用电荷耦合器件(CCD)和数字图像处理技术,实验研究了后向受激布里渊散射(SBS)光斑的光强分布,获得了其光强分布及光斑大小随入射能量的变化规律。结果表明,在入射光束为基模高斯光束的条件下,随着入射光能量增大,受激布里渊散射光斑的空间光强分布由近高斯型变为高斯型。并且受激布里渊散射光斑大小总体上是随着入射光能量的增大而逐渐减小的。当入射能量在受激布里渊散射阈值附近时,受激布里渊散射光斑大小达到最大(大于入射光斑);当入射能量为3倍阈值以上时,受激布里渊散射光斑大小达到最小(小于入射光斑)。
受激布里渊散射 空间光强分布 电荷耦合器件 光斑大小
1 哈尔滨工业大学可调谐激光技术国家级重点实验室, 黑龙江 哈尔滨 150001
2 西安应用光学研究所, 陕西 西安 710065
3 哈尔滨工业大学管理学院, 黑龙江 哈尔滨 150001
从理论和实验上对利用宽带KrF激光抽运SF6产生的受激布里渊散射(SBS)的脉宽稳定性进行了研究。获得了受激布里渊散射脉宽稳定性随抽运功率密度稳定性、抽运脉宽稳定性及介质气压变化的规律。发现受激布里渊散射脉宽的稳定性与抽运激光的稳定性直接相关,抽运激光的稳定性越好,获得的受激布里渊散射脉宽相对稳定性也越好。抽运光脉宽和能量的不稳定都会造成所产生的受激布里渊散射脉宽不稳定。在较低抽运功率密度情况下抽运光脉宽和能量的波动对受激布里渊散射脉宽稳定性的影响都不可忽略,但在较高抽运功率密度情况下受激布里渊散射脉宽稳定性主要受抽运光脉宽波动的影响。对结果进行了分析和讨论,获得脉宽稳定性较好的受激布里渊散射输出的条件是,使用脉宽稳定性较好的抽运光和在保证没有其他非线性效应产生的情况下,尽可能提高抽运光的功率密度和介质气压。
非线性光学 受激布里渊散射 脉宽稳定性 宽带KrF激光
Author Affiliations
Abstract
1 Institute of Opto-Electronics, Harbin Institute of Technology, Harbin 150001
2 Institute of Opto-Electronics, China Jiliang University, Hangzhou 310018
By adopting noise initiation model of stimulated Brillouin scattering (SBS), the influence of phonon lifetime and gain coefficient of medium on power limiting characteristic is numerically investigated. Through using actual parameters of three media, CCl4, acetone, and CS2, the waveforms of transmitted pulses are simulated. The result shows that different media have little effect on the front peak of waveform, while have an obvious effect on the height of power limiting platform. When the medium which has short phonon lifetime and small gain coefficient is used, the height of power limiting platform is comparatively high. In experiment, by focusing 1064-nm, 8-ns, 18-mJ pulses into these three media, the waveforms of transmitted pulses are obtained. The experimental results are in good agreement with conclusions of theoretical simulations.
受激布里渊散射 光限幅 布里渊介质 190.4360 Nonlinear optics, devices 290.5900 Scattering, stimulated Brillouin Chinese Optics Letters
2007, 5(11): 674
