共查询到18条相似文献,搜索用时 109 毫秒
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用摄动理论对超短超强脉冲激光产生的电离通道进行了研究.得出了在复合、吸附、退吸附作用影响下,电离通道在不同演化时期,各种带电粒子密度的渐近表达式.揭示了各种作用对通道存活性态的影响.
关键词:
密度
激光脉冲
等离子体通道
摄动 相似文献
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飞秒激光双脉冲在研究光泵浦的超快瞬态过程领域具有重要的应用价值,如何实现高准确度的飞秒激光双脉冲的实时测量显得尤为重要.本文提出了一种基于自相关法的飞秒激光双脉冲参量的测量方法,可实现对共光路传输、具有飞秒至皮秒级时间间隔的飞秒激光双脉冲的脉冲间隔、脉冲宽度和强度比的实时测量.实验中采用自相关仪测得了双折射晶体(钒酸钇)分束出的飞秒激光双脉冲的自相关曲线,并用非线性拟合算法求得了飞秒激光双脉冲的脉冲间隔、脉冲宽度和强度比参量.实验结果表明,本文方法与互相关测量方法相比,克服了参考脉冲参量的不确定性对检测准确度的影响,使测量平均准确度提高了48%以上. 相似文献
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飞秒激光双脉冲在研究光泵浦的超快瞬态过程领域具有重要的应用价值,如何实现高准确度的飞秒激光双脉冲的实时测量显得尤为重要.本文提出了一种基于自相关法的飞秒激光双脉冲参量的测量方法,可实现对共光路传输、具有飞秒至皮秒级时间间隔的飞秒激光双脉冲的脉冲间隔、脉冲宽度和强度比的实时测量.实验中采用自相关仪测得了双折射晶体(钒酸钇)分束出的飞秒激光双脉冲的自相关曲线,并用非线性拟合算法求得了飞秒激光双脉冲的脉冲间隔、脉冲宽度和强度比参量.实验结果表明,本文方法与互相关测量方法相比,克服了参考脉冲参量的不确定性对检测准确度的影响,使测量平均准确度提高了48%以上. 相似文献
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A simple and repeatable method using femtosecond laser pulse train to fabricate nanostructured substrates with silver nanoparticles over a large area for surface-enhanced Raman scattering is reported. The method involves two steps: (1)?femtosecond laser pulse train micromachining and roughening and (2)?femtosecond laser processing of the substrates in a silver nitrate solution. Surface modification is investigated experimentally by varying the time delay of the double femtosecond laser pulse train. With time delay ranging from 200 to 600?fs, the different enhancement factors were observed. This study demonstrates that a maximum enhancement factor of 6.8×106, measured by 10-6 M Rhodamine 6G solution, can be achieved at the time delay of 400?fs. 相似文献
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Visible femtosecond (fs) laser pulses have been obtained in a dye solution with a very simple traveling wave collinear configuration.
A femtosecond Ti:sapphire laser (790 nm) pumps the dye solution by two-photon absorption and simultaneously generates supercontinuum,
which seeds a light-amplification mechanism. Cross-correlation frequency-resolved optical gating measurements reveal a chirped
structure in the dye pulse. The shortest pulse duration achieved is 170 fs and the overall energy efficiency of the process
is typically 25%.
Received: 22 March 2001 / Revised version: 4 July 2001 / Published online: 19 September 2001 相似文献
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研制了一套基于多光子脉冲内干涉相位扫描方法的可以同时对飞秒激光脉冲进行相位测量和补偿的实验系统装置.实验中,通过自主研发的LabVIEW程序控制液晶空间光调制器和光纤光谱仪,对待测飞秒激光脉冲施加相位扫描,并同时记录受到调制的飞秒激光脉冲的倍频光谱,得到了多光子脉冲内干涉相位扫描(MIIPS)轨迹图.通过MIIPS轨迹图的三次测量和迭代运算,还原出了经过预先啁啾调制的中心波长约为810 nm、重复频率为1 kHz的飞秒激光脉冲的光谱相位,测量精度在0.1 rad以内.根据测量结果,利用液晶空间光调制器对该飞秒激光脉冲进行相位补偿,得到了近似傅里叶变换极限的飞秒激光脉冲.这一装置将在多光子显微成像、脉冲整形、飞秒激光光谱学等众多领域发挥重要作用. 相似文献
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Hiroshi Y. Yoshikawa Ryota Murai Syou Maki Tomoya Kitatani Shigeru Sugiyama Gen Sazaki Hiroaki Adachi Tsuyoshi Inoue Hiroyoshi Matsumura Kazufumi Takano Satoshi Murakami Takatomo Sasaki Yusuke Mori 《Applied Physics A: Materials Science & Processing》2008,93(4):911-915
We have investigated femtosecond laser-induced nucleation of hen egg-white lysozyme (HEWL) as a function of the laser pulse
energy and pulse time width. This is the first recorded study to confirm that the femtosecond laser-induced nucleation of
HEWL can be induced at a specific threshold laser energy. The threshold energy is comparable to that of cavitation bubble
generation. The results strongly suggest that morphological changes in the solution are key factors for protein nucleation. 相似文献