共查询到20条相似文献,搜索用时 270 毫秒
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分析了快脉冲直线型变压器驱动源(FLTD)气体开关触发击穿延时的分布规律,利用MAT-LAB软件生成随机序列模拟开关击穿延时和抖动,在FLTD简化二阶电路的基础上,利用MATLAB分析了开关抖动对40个支路并联1 MA,100 ns FLTD模块输出电流脉冲前沿和幅值的影响。模拟计算结果表明:开关理想时,即抖动为0,输出电流峰值为996 kA,峰值时间为90 ns,10%~90%脉冲前沿为54 ns;开关自身抖动与开关之间分散性之和为10 ns时,输出电流脉冲前沿增加约14%,电流峰值下降约2%;开关自身抖动与开关之间分散性之和为20 ns时,输出电流脉冲前沿增加约38%,电流峰值下降约5%。 相似文献
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为了提高高频段高功率微波反射面天线的馈电效率,同时使波束波导馈线更加紧凑,提出一种新型的X波段极化可重构高功率微波辐射器结构。通过波纹喇叭辐射器产生准高斯的HE11模辐射,采用双相位修正镜组成的波束变换系统实现将准高斯波束转换为电场分布更为均匀的平顶波束或其余期望分布的波束,平顶分布的输出波束可使得馈源在相同介质窗尺寸下获得更高的功率容量,同时实现了波束传播方向的90°转弯;此外采用双圆极化栅网的级联组合,实现了对输出波束极化特性的调变。通过全电磁波仿真分析验证了该辐射器的设计思路。 相似文献
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研究了一种通过改变波导内场分布的旋转对称性,可将高功率微波源输出的TEM模或TM01模转换为TE11模的径向线型模式变换器。介绍了该模式变换器的基本原理,即采用金属插板将同轴波导TEM模变换为4路90°扇形波导TE11模,各路扇形波导间所需的输出相位差通过将扇形波导转换为双层径向线传输来实现。基于这一原理,设计了一个中心频率为1.6 GHz的同轴TEM-TE11模式变换器,并进行了数值模拟计算,结果表明该模式变换器具有较高的功率容量,中心频率处反射系数为0.05,模式转换效率为99%,在1.52~1.68 GHz的频带范围内,模式转换效率大于90%。 相似文献
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为了探究角锥棱镜谐振腔激光模式,以角锥-平面镜腔为例,将角锥棱镜等效为衍射光栅,考虑角锥镜棱宽在谐振腔中的衍射效应以及二面角误差引起的附加相位分布对谐振腔激光模式的影响,在光学谐振腔理论的基础上,建立了求解本征模式的理论分析模型.采用快速傅里叶法数值模拟不同腔长、角锥镜棱宽和二面角误差情况下该无源谐振腔激光输出模式分布情况.结果表明,在腔长30 cm、角锥镜棱宽小于75μm、二面角误差在-10′~5′之间时,可实现光斑完整的圆形分布输出模式,且有较好的光束质量;棱宽不小于0.4 mm,二面角误差在-40′~10′之间时,光斑为TEM 03阶横模,光场呈六瓣分布;当角锥镜棱宽为0.4 mm、二面角误差为3′,腔长从30~90 cm范围内增加时,该谐振腔输出的激光模式从TEM 03转换成TEM 10. 相似文献
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We propose a scanning imaging measurement method using two linear array charge coupled devices (CCD) to evaluate the transmission performance of the linear laser beam of 90° × 2°. The two linear array CCDs are placed at two positions in the far field separated by a definite angle. The beam divergence angles in the view direction are measured by linear fitting because the beam width conforms to the linear relationship in the far field. This method has the ability for real-time testing and is appropriate for the complicated beam shapes with a wide measurement range. 相似文献
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S. Zhang L. Guo B. Xiong Y. Liu W. Hou X. Lin J. Li 《Applied physics. B, Lasers and optics》2011,104(4):861-866
A compact straight cavity with two side-pumped Nd:YAG laser heads and a 90° quartz rotator in between is presented. By intracavity-frequency-doubling
with a type II LBO crystal in this cavity, an output power of 180.2 W at 532 nm with a repetition rate of 10 kHz was achieved,
corresponding to an electrical-to-optical efficiency of 10.9%. To best of our knowledge, this is the highest electrical-to-optical
efficiency of the high power green lasers with above 100 W output power, ever reported. The pulsewidth was 70 ns and the peak
power was 257.4 kW. The beam parameter product (beam waist multiplied by half beam divergence angle) was estimated to be 4.2 mm mrad
and the power fluctuation over 2.5 hours was calculated to be better than ±1.2%. 相似文献
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M. Yorozu J. Yang Y. Okada T. Yanagida F. Sakai S. Ito A. Endo 《Applied physics. B, Lasers and optics》2003,76(3):293-297
Polarization-dependent spatial beam profiles of femtosecond X-ray pulses generated by a laser Compton scheme were measured.
The X-ray pulses were generated by the interaction at an angle of 90° between 100-fs laser light and a 3-ps, 3π-mm mrad electron
beam. The polarization of the laser light was linear in two different directions, either parallel or perpendicular to the
electron beam axis. The measured profiles showed good agreement with theoretical results.
Received: 5 July 2002 / Revised version: 17 October 2002 / Published online: 5 February 2003
RID="*"
ID="*"Corresponding author. Fax: +81-424/684477, E-mail: msf_yorozu@shi.co.jp 相似文献
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基于非线性光学理论,分析了1 064 nm和1 319 nm和频产生589 nm激光源的理论基础。针对LBO晶体的I类相位匹配条件及最佳晶体长度的选择进行了计算机数值模拟,给出了最佳晶体长度与总入射功率的关系曲线。当波矢量与光轴夹角为90°,波矢量方位角为3.39°时,计算出相应的有效和频系数为0.952×10-12 m/V。设计了一种简便高效的实验和频方案,二极管泵浦Nd:YAG激光器经腔镜镀膜及腔内可倾斜标准具调谐,分别输出了波长为1 064 nm和1 319 nm的准连续激光,然后通过脉冲同步调节,实现了589 nm黄光输出,平均功率达到500 mW,光束质量因子M2约2.1,和频效率18%。 相似文献
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M. Yorozu J. Yang Y. Okada T. Yanagida F. Sakai K. Takasago S. Ito A. Endo 《Applied physics. B, Lasers and optics》2002,74(4-5):327-331
A short-pulse X-ray-generation experiment was performed by Compton scattering through interaction between a 3-ps electron
beam and 100-fs laser photons in a 90° scattering configuration. The observed X-ray intensity was typically 3×104 photons/pulse and roughly matched the theoretically expected intensity. The X-ray energy and pulse duration were estimated
theoretically to be 2.3 keV and 280 fs from the observed electron- and laser-beam parameters. The fluctuation of the X-ray
output was measured as 25% (rms) during a 30-min operation. The fluctuation was expressed as a function of the fluctuation
of the timing between the electron and laser beams. The measured fluctuation of the X-rays was approximately consistent with
that caused by the fluctuation of the timing between the beams.
Received: 19 November 2001 / Revised version: 23 January 2002 / Published online: 14 March 2002 相似文献
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M. Garçon D. Legrand R.M. Lombard B. Mayer M. Rouger Y. Terrien A. Nakach 《Nuclear Physics A》1985,445(4):669-684
Using an internal jet target in the Saturne synchrotron, we have measured the proton-proton differential elastic cross section at 90° c.m. as a continuous function of energy (from 500 to 1200 MeV) during the acceleration of the beam. The energy resolution is about 2 MeV. The results are compared to predictions of phase-shift analyses and discussed in connection with amplitude analyses at 90° c.m. No resonant structure was observed and no evidence for narrow dibaryons was found. 相似文献
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Periodic arrays of submicron Si and Ni dots were fabricated by only irradiating a linearly polarized Nd:YAG pulsed laser beam
to Si and Ni thin films deposited on silicon dioxide (SiO2) film. The interference between an incident beam and a scattered surface wave leads to the spatial periodicity of beam energy
density distribution on the surface of the irradiated samples. A thin film was melted using a laser beam, and the molten film
was split and condensed owing to its surface tensile according to the periodic energy density distribution. Then, the fine
lines (line and space structure) were formed periodically. After the formation of fine lines, the sample was rotated by 90°,
and the laser beam was irradiated. The periodic energy density distribution was generated on the fine lines, and the lines
were split and condensed. Eventually, the periodically aligned submicron dots were fabricated on the SiO2 film.
PACS 79.20.Ds; 42.62.-b; 81.40.-z 相似文献
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光纤激光是继气体激光、化学激光和固体激光之后的新一代激光技术,是近年来世界各国科学研究的热点领域。制约光纤激光功率提升的主要技术瓶颈是系统集成技术和光纤材料制备技术。目前,我国科研工作者成功掌握了千瓦级光纤激光系统集成技术并实现了产业化,但是所用的光纤激光材料与核心器件还严重依赖进口。相较于比较成熟的系统集成技术,我国光纤激光材料的科学研究和产业化进程相对滞后,尚无法提供成熟稳定的有源光纤产品。 2016年6月,中国工程物理研究院激光聚变研究中心的研究人员经过近三年科研攻关,成功研发了30/900规格(纤芯30 m/包层900 m)镱掺杂铝磷硅(Yb-APS)三元体系激光光纤并实现了6.03 kW最高功率输出,在5 kW功率水平下可长期稳定工作。光纤激光材料综合测试平台采用了传统的1+1型MOPA放大结构(即信号种子源与一级主放):信号光种子源的功率为40 W,光束质量M2=1.1;第二级MOPA放大级使用的976 nm LD泵浦光总功率9.95 kW,经过CPS功率剥离器激光净化处理后,最终安全地实现了6.03 kW最大功率输出。如图1所示,最高输出功率时斜率效率为61.25%,源于1∶30的芯包比和20 m以上的光纤使用长度;激光输出光谱中心波长1080 nm,3 dB带宽为1.89 nm,受激拉曼抑制比>15 dB;5 kW稳定工作时,光束质量M2=2.38,未发现光子暗化效应。中物院激光聚变研究中心所研制的镱掺杂铝磷硅三元体系有源光纤(30/900 Yb-APS fiber)成功实现了6.03 kW激光输出,是我国高功率光纤激光材料研究领域的重要进步,为制备低损耗、高掺杂、高吸收、高增益、无光子暗化效应的商业激光光纤产品奠定了坚实的技术基础。 相似文献
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F. Keilmann 《Optics Communications》1975,14(2):236-237
We report on a seven-mirror device usable for flipping the linear polarization of a laser beam by 90°. It works over a broad spectral range in the infrared and can withstand high power. Also, flipping by angles other than 90° is possible at the expense of introducing small elliptical polarization. 相似文献
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Development of master oscillator power amplifier (MOPA) system of copper bromide laser (CBL) operating at 110 W average power is reported. The spectral distribution of power at green (510.6 nm) and yellow (578.2 nm) components in the output of a copper bromide laser is studied as a function of operating parameters. The electrical input power was varied from 2.6 to 4.3 kW, the pulse repetition frequency (PRF) was changed from 16 to 19 kHz, and the pressure of the buffer gas (neon) was kept fixed at 20 mbar. When the electrical input power was increased to 4.3 kW from 2.6 kW, the tube-wall temperature also increased to 488°C from 426°C but the ratio of the green to yellow power decreased to 1.53 from 3.73. The ratio of green to yellow power decreased to 1.53 from 1.63 when the PRF of the laser was increased to 19 kHz from 16 kHz. These observations are explained in terms of electron temperature, energy levels of transitions, and voltage and current waveforms across the laser head. 相似文献