共查询到20条相似文献,搜索用时 93 毫秒
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基于极紫外波段高次谐波产生(high-order harmonic generation, HHG)的光学选通技术已成为目前人们获得孤立阿秒脉冲(isolated attosecond pulse, IAP)的重要手段。由于IAP继承了驱动激光脉冲的光学属性和重复频率,因此具有良好的时空相干性和方向性。近转换极限极短脉宽IAP的产生不仅需要在极紫外区域有较宽的连续光谱支持,还需要对其所携带的本征色散进行补偿。据此,本文从理论上模拟计算了多组阿秒脉冲光谱、本征色散和金属膜材料色散的参数组合,在中心光谱98,120,170 eV附近的结果表明,选用不同厚度的锆膜、钼膜和锡膜对应中心能量的高次谐波可以实现色散补偿。最终确定120 eV中心光子能量加钼膜的组合有可能在较高的产生效率下产生近40 as的IAP。基于上述参数选择,设计了一套由非共线阿秒条纹相机和平场光谱仪组成的极紫外阿秒束线及相应的真空系统,该系统可用于高次谐波及阿秒脉冲的测量。 相似文献
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对具有频率啁啾的飞秒脉冲的干涉场分布特性进行了研究。分别模拟了物光存在啁啾、参考光存在啁啾以及物光与参考光均存在啁啾3种情况下高斯飞秒脉冲的干涉图,并从干涉图中提取了载频相位。通过对提取的载频相位分析,研究了频率啁啾对干涉场的影响。结果表明,脉冲的频率啁啾将导致干涉条纹对比度的下降和条纹周期的改变。当物光和参考光仅有一束存在啁啾时,干涉场条纹的对比度整体下降,并且条纹周期发生线性改变;当物光与参考光同时具有相同的频率啁啾时,位于干涉场边缘的条纹的衬比度会严重下降,这将导致干涉场的有效记录区域减小。本文研究对于飞秒数字全息的实验控制和数字重构精度均具有重要的参考价值。 相似文献
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在电子汤普孙散射的经典理论的基础上,通过理论分析和计算机模拟,研究圆偏振周期量级激光脉冲作用下电子辐射的空间分布特性,提出可能的应用方向。研究发现,在相对论光强下,随着激光强度的增强,电子辐射逐渐增强,能量不断的向辐射中心集中,辐射能量分布的方向性逐渐突出;当改变激光的初相位时,电子辐射的总体方向发生偏移,表现为辐射分布图形的对称平面发生旋转,且旋转角度与激光初相位角改变大小相同。本文所进行的相关探讨基于电子辐射的三维空间立体图,所得到的有关电子谐波辐射的结论,可以为实验和工程上对电子辐射和激光参数测量的相关应用提供参考。 相似文献
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A neodymium glass laser system capable of generating high-energy, ultrashort pulses at a convenient repetition rate is described. The effect of nonlinear frequency pulling on active mode locking is discussed. By minimizing the nonlinear frequency pulling, it is possible to routinely generate stable ~10-ps pulses at a 100-MHz repetition rate from the actively mode-locked oscillator. The regenerator amplifier increases the oscillator pulse energy to over 30 μJ at a 370-Hz repetition rate. Using intracavity self-phase modulation, the regenerative amplifier also broadens the pulse bandwidth to ~35 Å. By subsequent pulse compression while maintaining high energy, it is possible to produce 0.55-ps pulses with >10 μJ. An optical fiber pulse compressor further shortens the pulses to 30 fs (30 nJ), the shortest pulses ever generated at 1.054 μm from a neodymium laser system 相似文献
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Wavelength-tunable very high power soliton fibre lasers are constructed using chirped fibre Bragg gratings. Near-bandwidth limited pulses with widths of 4.0 ps and pulse energies up to 10 nJ are generated directly from passively modelocked erbium fibre lasers. A stable pulse repetition rate of 17 MHz is obtained, giving rise to an average modelocked output power of 170 mW 相似文献
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采用被动锁模染料激光器作为振荡器,其输出为2~10微微秒的锁模脉冲系列,单脉冲能 量为5~10微焦耳。用XeCl准分子激光器泵浦的染料激光放大器放大,同时利用染料激光器可调谐特性,将其准确地调到616毫微米处,倍频后刚好落在XeCl准分子激光器的最大增益带宽中心,再经XeCl激光器放大后,可获得波长为308毫微米,带宽0.2毫微米,脉宽小于10微微秒,能量为8~10毫焦耳的紫外激光单一脉冲输出。 相似文献
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Picosecond pulses are generated in a diffraction-limited beam from passive (hybrid) modelocked conventional ( lambda =0.8 mu m) diode laser arrays in an external cavity. The emitted energy (10-20 pJ) is almost one order of magnitude higher than that obtained from single stripe quantum well lasers at similar pulse durations. The shortest pulses ( approximately 3 ps, 3 nm spectral width) are obtained with strong saturable absorbers and 1% antireflection coatings. Correspondingly, external cavities with relatively low angular selectivity can be used in these conditions.<> 相似文献
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《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1972,60(9):1107-1109
The first experimental demonstration of the generation of a radially polarized optical beam mode by laser oscillation is reported. In the experiment, a new type of discharge tube having the optical windows perpendicular to the optic axis is used, and a newly designed conical mode selector is inserted in the optical resonator. 相似文献
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Generation of <3 ps full width at half maximum (FWHM) 1.3 mu m pulses by compressing the chirped output of a gain-switched distributed feedback laser diode (DFB-LD) with a fibre dispersive delay line is reported. Diode laser requirements for minimum pulse width and maximum pulse energy, as well as suppression of 'wings' on the optical pulse, are discussed.<> 相似文献