共查询到18条相似文献,搜索用时 81 毫秒
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研究了C60/PMMA对波长532nm,脉冲宽度为21ps的脉冲激光的限幅特性,并应用三能级模型进行了理论模拟。结果表明光限幅起源于单重态发态吸收。 相似文献
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PDATS对ps脉冲的光限幅效应 总被引:1,自引:0,他引:1
应用脉宽为21ps脉冲,波长为532nm的激光脉冲研究了新型光限幅材料5-(2-硫甲基-4-甲基-5-嘧啶基)-2,4-戊二炔-1醇的对甲苯磺酸酯的光限幅效应,其优点是限幅幅值和限幅阈值低,分别为Ec=180mJ/cm^2,Eth=150mJ/cm^2;可见了光透射率高。 相似文献
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采用布里渊噪声起源模型,数值模拟了受激布里渊散射介质CCl4对波长1064nm的Nd:YAG纳秒激光脉冲的传输特性及光限幅特性。入射抽运脉冲能量较低时,非线性介质对纳秒激光脉冲呈光学透明。入射抽运脉冲能量高于受激布里渊散射产生阈值后,透射脉冲峰值受限,脉宽压缩,能量趋于饱和,说明该光学系统同时具有光功率限幅和能量限幅的光限幅特性。利用理论模型模拟了如下光限幅参量:透射脉冲峰值功率、透射能量、能量透射率、脉宽压缩率依赖抽运光能量的变化关系。相应的理论模拟计算结果由实验进行验证,实验结果与理论模拟相符合。 相似文献
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萘酞菁铅化合物的光限幅特性研究 总被引:6,自引:0,他引:6
应用调Q倍频ns/ps Nd:YAG脉冲激光,在波长为532nm,脉冲宽度为8ns,重复频率为1Hz的条件下,研究了溶于二甲基亚砜(DMSO)中的萘酞菁铅溶液的反饱和吸收和光限幅特性。实验表明,萘酞菁铅具有良好的光限幅特性,它的有效激发态吸收截面与基态吸收截面的比值约为15.21,大于萘酞菁铜。研究结果表明,萘酞菁铅的光限幅特性优于C60,激发态吸收是其主要的光限幅机理。实验结果证实了重原子效应可以通过增强系际跃迁而使三重态的反饱和吸收增强,从而提高光限幅的能力。 相似文献
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利用实验的方法研究了甲基红掺杂碳纳米管悬浮液对波长为532 nm激光的光限幅效应.分析了样品厚度和入射激光重复频率对光限幅特性的影响,并与纯碳纳米管悬浮液的光限幅特性进行了比较.实验结果表明,对于线性透过率为60%(500 nm)的碳纳米管悬浮液,掺入甲基红后其沉淀速度明显减慢,限幅阈值由250 μJ降低为200 μJ;对于2和5 mm 厚度的样品,掺杂甲基红使碳纳米管悬浮液的箝位输出激光脉冲能量分别由45和20 μJ降低为35和9 μJ.
关键词:
非线性光学
光限幅效应
甲基红
染料掺杂碳纳米管悬浮液 相似文献
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Study on the optical limiting properties of the mixed liquid of carbon black suspensions and
green tea solution by multi-pulse laser 下载免费PDF全文
The optical limiting properties of the mixed liquid of carbon black
suspensions (CBS) and green tea solution were studied by using an 8
ns laser pulse at 532\,nm. The optical limiting effects of the CBS
and mixed liquid have been compared between 5 and 10\,Hz repetition
frequencies with nanosecond laser pulse. The experimental results
indicate that the optical limiting threshold of the sample with the
incidence laser at 10\,Hz repetition frequency is lower than at
5\,Hz repetition frequency. The possible reasons for the influence
of the repetition frequency on the samples are discussed. And by
observing the optical radiant distributions when the laser pulse
passing through different samples, a possible mechanism for the
observed effects is suggested. At the same time, the result shows
that the optical limiting of CBS is the dominant factor to optical
limiting of the mixed liquid. 相似文献
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Pulse duration and wavelength effects on the optical limiting behavior of carbon nanotube suspensions 总被引:3,自引:0,他引:3
We investigate pulse duration and wavelength effects on the optical limiting behavior of single-wall carbon nanotubes suspended either in chloroform or in water. The principal optical limiting effect in carbon nanotube suspensions is nonlinear scattering that is due to heat transfer from particles to solvent, leading to solvent-bubble formation and to sublimation of carbon nanotubes. We report on nonlinear transmittance measurements for pulse durations ranging from 3 to 100 ns and for wavelengths from 430 to 1064 nm. The dependence of optical limiting behavior on pulse duration and wavelength is analyzed and discussed in terms of nonlinear mechanisms. 相似文献
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超短飞秒脉冲激光(脉冲时间<40 fs)有独特的热效应机理, 但尚无针对其设计的光限幅保护膜. 本文采用易于产业化的离散-旋涂法制备了MoS2纳微薄膜(厚度150–200 nm). 光限幅测试结果表明, 针对超短脉冲激光, 此纳微薄膜在低光强下增透, 高光强下减透(光限幅); 且能通过改变入射波长, 调控其光限幅阈值, 可用于聚光太阳能电池的效率增强和损伤保护.利用此方法, 对已商用的砷化镓太阳能电池进行涂膜, 发现转换效率降低<3%, 但损伤阈值提高>50%. 相似文献
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Nonlinear optical limiting materials have attracted much research interest in recent years. Carbon nanoparticles suspended
in liquids show a strong nonlinear optical limiting function. It is important to investigate the nonlinear optical limiting
process of carbon nanoparticles for further improving their nonlinear optical limiting performance. In this study, carbon
nanoparticles were prepared by laser ablation of a carbon target in tetrahydrofuran (THF). Optical limiting properties of
the samples were studied with 532-nm laser light, which is in the most sensitive wavelength band for human eyes. The shape
of the laser pulse plays an important role for initializing the nonlinear optical limiting effect. Time-resolved analysis
of laser pulses discovered 3 fluence stages of optical limiting. Theoretical simulation indicates that the optical limiting
is initialized by a near-field optical enhancement effect. 相似文献
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线阵CCD用于长距离衍射准直测量 总被引:2,自引:0,他引:2
本文介绍了在半导体激光光纤与位相板相结合的准直情况下,利用线阵CCD探测器测量大型工件形位误差遇到的光强变化而引起测量误差的问题,并对用线阵CCD进行衍射信号测量的原理和特点作了分析。根据CCD的工作原理和特性,提出了利用自动控制CCD积分时间的方法,使CCD输出的信号峰值保持恒定,提高了系统的测量精度。 相似文献
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M. O. Baumgartner D. P. Scherrer F. K. Kneubühl 《Applied physics. B, Lasers and optics》1996,62(5):473-477
We report on optical limiting and z-scan in CS2 as a function of the pulse duration of 10 µm TEA CO2-laser radiation. We present a comprehensive and simple model for the shape of a laser pulse transmitted through this limiting device. For the first time, we propose the use of an optical limiting device for beam shaping. 相似文献