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时间分辨飞秒相干光谱技术的发展与展望 总被引:1,自引:1,他引:0
本文概述超短脉冲激光相干光谱技术的基本原理及发展分析了与这些技术相关的理论,同时指出了以往相干光谱技术中存在的问题。针对本课题组fs或亚氏fs相干光谱实验技术中存在的主要问题提出了具体的改进思路;减少延时线的误差,提高泵浦和探测光斑在样品上的重合度;对探测光进行调制;获取fs脉冲激光与物质相互作用的振幅、相位和波矢的信息;对相干光谱的实验结果进行多方位的理论分析。 相似文献
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光在一维周期结构中的分布和局域化 总被引:10,自引:8,他引:2
运用传播矩阵对不同种类的一维周期结构(periodic structure, PS)中的光场分布和局域化进行了理论分析.结果表明: 当光以禁带频率入射到PS上时,绝大部分光被反射,在PS中是以衰减的驻波形式存在的.需要强调的是,当光以禁带带边频率入射时,光场在PS中有显著的局域化,在介质中引入适当的缺陷可以极大地增加这种局域化程度.另外,当光从掺杂有特定缺陷层的PS的左右两个不同界面入射时,可引起光场在PS中不同的分布,这对通过光的非线性调制实现的光学二极管非常有用.在线性吸收的PS中光强随光进入介质的厚度及消光系数的增加迅速衰减. 相似文献
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The spectral resolved femtosecond pump-probe experiment is applied to measure the third order nonlinear refractive index coefficient, two-photon absorption coefficient of GaP crystal, and the chirp parameter of the input laser pulses. The results show that nonlinear refractive index coefficient is 2× 10-18 m2/W, twophoton absorption coefficient is 2× 10-11 m/W at wavelength of 783.5 nm, and the chirp parameter of laser pulse is l× 1025 s-2. Furthermore, the mechanism of nonlinear refraction due to two-photon absorption in GaP crystal and experimental results are discussed. 相似文献
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The spectral resolved femtosecond pump-probe experiment is applied to measure the third order nonlinear refractive index coefficient, two-photon absorption coefficient of GaP crystal, and the chirp parameter of the input laser pulses. The results show that nonlinear refractive index coefficient is 2 × 10 -18 m2/W, two-photon absorption coefficient is 2×10-11 m/W at wavelength of 783.5 nm, and the chirp parameter of laser pulse is 1×1025 s-2. Furthermore, the mechanism of nonlinear refraction due to two-photon absorption in GaP crystal and experimental results are discussed. 相似文献
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非线性光子晶体的单向透射性 总被引:2,自引:1,他引:1
利用非线性时域有限差分方法(FDTD)对光从某些一维缺陷层掺杂克尔非线性介质的四分之一波长光子晶体的正反两个不同方向入射时对应的一般透射特性进行了数值分析.计算表明:一定频率范围及一定光强范围的光从非线性光子晶体的正向入射时,透射率是其从非线性光子晶体相反方向入射时的数倍,具有单向透射性,表现为全光二极管的行为.进一步对交替介质层由空气和金红石(TiO2)组成而非线性缺陷层由聚合物(polydiacetykene 9-BCMU)组成的光子晶体模型的透射特性进行了数值分析.在某一频率和强度附近,该模型的正向透射率是反向的6倍左右,表明其可作为一种全光二极管使用. 相似文献
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Direct calculations of absorption spectra for multi-quantum well structures by extracting field distributions at well positions are performed. Results demonstrate the previously reported Bragg suppression, and agree exactly with the indirect calculation by linear dispersion theory. This reveals that Bragg suppression effect in fact originates from the remarkably decreased intensities at well positions by Bragg interference condition, rather than from the formation of supperradiant modes. 相似文献
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