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全固态激光器14 kHz Q脉冲实验研究 总被引:3,自引:0,他引:3
在激光二极管抽运固体激光器(DPSSL)中设计一种由无刷电机驱动,采用棱镜作为旋转反射镜的转镜Q开关。设计了20只棱镜的转盘,获得重复频率14.3 kHz的激光脉冲,实现了千赫兹高重复频率大功率关断能力的Q开关技术。在逐步提高转镜转速来缩短Q开关时间的实验中,激光脉冲序列相应递减,当棱镜转镜转速为4.3×104r/min时,获得脉宽89 ns,重复频率14.3 kHz的1064 nm高重复频率脉冲输出。当输入功率为795 W时,获得平均功率100 W脉冲输出,电-光转换效率为12.5%,峰值功率达到78.3 kW。实验结果说明,棱镜转镜Q开关是实现全固态激光器千赫兹Q脉冲输出的可行技术途径之一。 相似文献
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中科院近代物理研究所科研人员经过8个多月的艰苦努力,完成了ADS超导质子直线加速器注入器II的半波长谐振(HWR)型超导铌腔整腔的加工,并进行了常温下的真空和频率测试,表明该腔体的研制取得了重要的阶段性进展。HWR型超导铌腔的研制完成了工艺设计、冲压成形、加工矫形、频率预调谐、零部件酸洗、电子束焊接等工序,在哈尔滨工业大学先进焊接与连接 相似文献
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报道了一种基于金纳米笼可饱和吸收体的3 μm被动词Q光纤激光器.采用结构紧凑的线型腔设计,在钬镨共掺光纤中实现了稳定的调Q脉冲激光运转.当泵浦功率达到99.7 mW时,开始出现稳定调Q状态,重复频率为82.0 kHz.当泵浦功率达到347.1 mW时,得到的最大平均输出功率为50.7 mW,最短脉冲宽度为2.21 μs,对应的重复频率为169.5 kHz.实验结果表明,金纳米笼在中红外波段光纤激光器中具有良好的应用前景. 相似文献
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20Mn-13Cr-5Ni-0.25N钢是为大型超导装置研制的奥氏体低温结构钢,在77K温度时达到了高强度高韧性。钢在77K断裂呈准解理特征,断口边缘变形区中观察到奥氏体内有滑移线生成。为研究钢的低温断裂机制,对滑移线进行了SEM、TEM分析。 相似文献
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高温超导体纤维有重要的应用前景,得到人们很大的重视。本课题组用激光加热基座生长法(LHPG)制备了性能优异的Bi基Bi-Sr-Co-Cu-O及Bi-Pb-Sr-Ca-Cu-O超导纤维,超导的零电阻温度T_(co)为85K及108K,临界电流密度Jc已达到了5150A/cm~2。本文研究了这种超导纤维的结构。图1为材料源棒与激光熔化生长纤维的过渡区,图中S为源棒,G为溶化成纤区。激光束使原晶体熔化,选用适当的仔晶,从熔化区提拉生长出晶休纤维。生成的纤维有很好的取向性,x衍射分析表明,纤维轴向主要是晶体的[001]方向。图2是超导纤维横断面的扫描电镜照片,Bi系超导晶体一般成片状结构,纤维中的晶粒尺度较大,当晶片紧密堆砌时,材料的密度较高,对获得较高的Jc有利,当晶片的取 相似文献
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Research on the magnetron cavity used in the rubidium atomic frequency standards is developed, through which the main characteristic parameters of the magnetron cavity are studied,mainly including the resonant frequency,quality factor and oscillation mode.The resonant frequency and quality factor of the magnetron cavity were calculated,and the test results of the resonant frequency agreed well with the calculation theory.The test results also show that the resonant frequency of the magnetron cavity can be attenuated to 6.835 GHz,which is the resonant frequency of the rubidium atoms,and the Q-factor can be attenuated to 500-1000.The oscillation mode is a typical TE011 mode and is the correct mode needed for the rubidium atomic frequency standard.Therefore these derivative magnetron cavities meet the requirements of the rubidium atomic frequency standards well. 相似文献
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《Microwave Theory and Techniques》1972,20(1):30-37
One of the most promising techniques for measuring the electric permittivity at microwave frequencies of thin dielectric materials of the order of 0.1 to 10 /spl mu/m, is the cavity perturbation method. For thin films of this type, it is necessary to determine accurately and display small changes in the resonant frequency and Q factor of the cavity in the presence of the material sample. A circuit for the simultaneous measurement and digital readout of the resonant frequency and Q factor of microwave cavity is described. For the resonant frequency measurement, a very efficient automatic frequency circuit, with a homodyne modulation-detection bridge and frequency stabilization loop, is applied. Theoretical analysis and experiments results with this circuit show that an accuracy of 5x10/sup -7/can be achieved in the resonant frequency measurement. For measuring the Q factor, two similar circuits are described. The technique is based on measuring the phase shift of the envelope of an amplitude modulated microwave signal when this signal is transmitted through a resonant cavity at resonance. Although an accuracy of 0.5 percent in the Q factor can be achieved, it is shown that the main limiting factor in both circuits is the accuracy of phase shift determination at RF frequencies. 相似文献
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采用有限元方法计算了二维方形介质腔和二维微盘的谐振频率和品质因子,并给出了两种腔中磁场、电场振幅分布图,介质腔中的谐振问题对应亥姆霍兹波动方程的本征值问题,本征值的实部和虚部与谐振腔Q值关联;比较了近似解析解、FDTD解、FEM解的结果,对于谐振频率比较,FEM和解析解更接近,对于品质因子比较,低Q值结果FDTD和FEM结果相近,高Q值结果两者相差较大。通过比较知道,FEM方法比时域有限差分方法计算更准确,求解速度更快。 相似文献
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W 波段回旋振荡管是一种重要的高功率毫米波源,它通常采用圆柱开放式谐振腔作为其高频结构。
谐振腔所具有的特性参数,如谐振频率和品质因数影响了整管的性能。在W 波段,特性参数对于尺寸的变化特别敏
感,因此,有必要对加工好的开放式谐振腔的特性参数进行测量。利用直接耦合法实现了对5 组开放式谐振腔谐振
频率和品质因数的无损检测,实验结果验证了该方法的可行性与有效性。同时,分析了加工误差对谐振腔性能造成
的影响,结果表明,当开放式谐振腔渐变角度的加工误差达到7%以上时,谐振频率将偏移0.2GHz。 相似文献