共查询到19条相似文献,搜索用时 78 毫秒
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利用铜蒸气激光器泵浦碰撞锁模染料激光放大器,获得2.4μJ,70 fs低色散光脉冲,脉冲重复率为5kHz. 相似文献
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本文报道了在较低的泵浦功率密度(10^10W/cm^2)产生光谱连续覆盖(400~870)nm,持续时间为80fs,重复频率为8kHz的高重复频率“白光”超短脉冲的实际实验系统。 相似文献
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对高能量掺镱激光器进行腔外压缩,是获得高能量少数周期脉冲的重要方式。通过数值模拟研究了单脉冲能量为250 mJ,波长为1 030 nm的高能量掺镱激光器通过固体多薄片介质进行非线性脉冲压缩的过程,及介质周期、厚度对频谱展宽的影响。在优化频谱展宽条件的过程中发现,不超过介质损伤阈值的情况下,固体薄片组的周期和厚度对频谱展宽具有正向影响。通过选取合适的介质厚度及周期,激光频谱通过熔融石英介质进行展宽,最终输出的光谱带宽达229 nm,补偿色散后,激光脉冲由500 fs压缩至16.2 fs,压缩比达到30。研究结果为实现高能量激光脉冲的非线性压缩提供了理论参考。 相似文献
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Femtosecond optical pulses generated from a synchronously pumped fiber Raman soliton laser (FRASL) have been shown to have large excess noise and high background light (i.e., the pedestal) levels. In this paper, to improve the FRASL, the operation characteristics of the FRASL are investigated both theoretically and experimentally. It is shown that real femtosecond soliton oscillation in the FRASL can be obtained only when the soliton self-frequency shift (SSFS) effect in the fibers is suppressed and proper choices of both the Stokes oscillation wavelength and the pump power level are required for the SSFS suppression in the FRASL. By using a tunable all-fiber Raman ring laser, optical pulses as short as 400 fs with a low white AM noise level of -120 dBc / Hz have been generated from the compact FRASL with SSFS suppression. Based on the theoretical analyses, we propose to use an intracavity saturable absorber to prevent the generation of high-level Stokes background light in the FRASL, and the feasibility of this method is shown by numerical simulations. 相似文献
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Propagation of bright femtosecond pulses in a nonlinear optical fibre with the third- and fourth-order dispersions 下载免费PDF全文
We solve the generalized nonlinear Schr\"{o}dinger equation
describing the propagation of femtosecond pulses in a nonlinear
optical fibre with higher-order dispersions by using the direct
approach to perturbation for bright solitons, and discuss the
combined effects of the third- and fourth-order dispersions on
velocity, temporal intensity distribution and peak intensity of
femtosecond pulses. It is noticeable that the combined effects of the
third- and fourth-order dispersions on an initial propagated soliton
can partially compensate each other, which seems to be significant
for the stability controlling of soliton propagation features. 相似文献
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为进一步提高光存储密度,利用固体侵没透镜(SIL)与数值孔径为0.55的长工作距离物镜对飞秒激光脉冲进行聚焦,完成了PMMA及石英介质上的存储实验,并对聚焦物镜焦点与SIL底面离焦时的介质内焦点位置和系统的数值孔径进行了模拟。实验结果表明:当聚焦物镜焦点与SIL底面适当离焦时,实际聚焦在介质内的焦点深度不断加深,且系统的有效数值孔径不断增大。利用这一结果,在距PMMA表面20μm的地方得到了点间距1μm,层间距2.5μm的6层空间点阵;在距石英介质表面15μm的地方获得了点间距为0.6μm,层间距为2.5μm的5层空间点阵,其存储密度可达1.1×1012bits/cm3。 相似文献
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采用放电泵浦KrF准分子激光放大器放大波长为248.4nm的紫外超短脉冲激光。对于能量为0.7mJ、脉宽为550fs的输入脉冲,在光束直径保持10mm不变的条件下,能量放大到15mJ,脉宽展宽到1200fs。为了压缩输出脉冲宽度,分析了群速度色散和自相位调制效应对脉宽展宽的影响。利用棱镜对,采用4种不同的实验方案对脉冲引入负的线性频率啁啾,以补偿KrF准分子激光放大器CaF2窗镜中的群速度色散和自相位调制对脉冲引入的正的线性频率啁啾。结果表明:在放大器之前放置棱镜对的方式可以在保持输出脉冲能量为15mJ的同时,在棱镜对间距为110cm的条件下,将输出脉冲宽度压缩到370fs,输出波长为248.4nm、带宽为0.4nm。 相似文献
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用数值方法研究了各阶克尔非线性折射系数对强激光传输的影响,结果显示第7阶克尔非线性系数和第9阶克尔非线性系数协同影响激光传输,当第7阶克尔效应起作用时,忽略第9阶克尔效应的作用会导致光强随传输距离震荡剧烈,传输非常不稳定。要得到稳定传输需要第7阶克尔非线性系数和第9阶克尔非线性系数同时起作用或同时不起作用。在自聚焦阶段第3阶非线性折射率对折射率改变起主要作用,在稳定光丝传输阶段第7阶克尔非线性系数,第9阶克尔非线性系数起主要作用。第5阶克尔系数在整个传输过程中对折射率的改变一直比较小。 相似文献