Coherent phonon generation by light pulse train and Optical control of material propeties

光脉冲串产生相干声子和材料特性的光学控制

• 批准号: 10440092
• 负责人: KINASLUTAL Shuichi
• 金额: $ 6.72万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10440092/
• 关键词: Femtosecont pulse; coherent phonon; four-wavemixing; Pulse shaping; Stimulated Raman scattering; フェムト秒光パルマ; フーリエ変換波型整形法; Ti:サファイアレーザー

The frequency modes below 3 THz in materials are called "low frequency modes" in light scattering experiment and are known to relate directly with the material properties. In liquid, the low frequency phonon modes and the relaxational mode dominate over this region. The relaxational mode is peculiar to liquid state and is believed to play an important role in connecting the microscopic degrees of freedom with the macroscopic quantities.In the present work, we have developed various methods to create multipulses; directly created by slightly detuned laser cavity and by employing the Fourier transform pulse shaping apparatus. Particularly we have divided an amplified pulse into two, which are applied independently by the amplitude modulations to create two-color synchronous pulses. Using these pulses, we have observed the diffraction from the moving grating in the four-wave mixing configuration. This method is particularly suitable for the selective excitation of the phonon modes without exciting the relaxational mode.We further perform the frequency-domain four-wave mixing (FD4WM) spectroscopy by employing a Q-switched YLF laser synchronously oscillating as a probe. It is found that this spectroscopy efficiently offers the information on the frequency response excited by the pump pulses and becomes suitable to observe the phonon dynamics after selective excitation.

材料中低于 3 THz 的频率模式在光散射实验中被称为“低频模式”，已知与材料特性直接相关。在液体中，低频声子模式和弛豫模式在该区域占主导地位。弛豫模式是液态所特有的，被认为在连接微观自由度与宏观数量方面发挥着重要作用。在目前的工作中，我们开发了各种方法来创建多脉冲；直接由稍微失谐的激光腔和使用傅里叶变换脉冲整形装置产生。特别是，我们将放大的脉冲分成两部分，通过幅度调制独立地应用它们以创建双色同步脉冲。使用这些脉冲，我们观察到了四波混频配置中移动光栅的衍射。该方法特别适合于选择性激发声子模式而不激发弛豫模式。我们进一步采用同步振荡的调Q YLF激光器作为探针进行频域四波混频（FD4WM）光谱。研究发现，这种光谱有效地提供了泵浦脉冲激发的频率响应信息，并且适合观察选择性激发后的声子动力学。

项目成果

J. Watanabe, Y. Watanabe, M.Tango and S. Kinoshita: "Discrepancy in response functions obtained from Stokes and Anti-Stokes low frequency light scattering in liquid"J. Luminescence. (印刷中). (2000)

J. Watanabe、Y. Watanabe、M.Tango 和 S. Kinoshita：“从液体中的斯托克斯和反斯托克斯低频光散射中获得的响应函数的差异”（出版中）。

S. Kinoshita, Y. Kai, Y. Watanabe: "Origin of initial rise process of ultrafast exponential response in liquids"Chem. Plup. Lett.. 301. 183-188 (1999)

S. Kinoshita、Y. Kai、Y. Watanabe：“液体中超快指数响应的初始上升过程的起源”Chem。

J. Watanabe, Y. Watanabe, M. Tango and S. Kinoshita: "Discrepancy in response functions obtained from Stokes and anti-Stokes lowfrequency light scattering in liquid"J. Luminescence. (to be published).

J. Watanabe、Y. Watanabe、M. Tango 和 S. Kinoshita：“从液体中斯托克斯和反斯托克斯低频光散射获得的响应函数的差异”

Y. Kanematsu, H. Ozawa, I. Tanaka and S. Kinoshita: "Femtosecond optical Kerr-gate measurement of fluorescence spectra of dye solutions"J. Luminescence. (to be published).

Y. Kanematsu、H. Ozawa、I. Tanaka 和 S. Kinoshita：“染料溶液荧光光谱的飞秒光学克尔门测量”J。

H. Fukuda and S. Kinoshita: "Coupling of Macroscopic Quantities in Liquid Observed by Brillouin Spectroscopy"J. Kor. Phys. Soc.. 35. S1141-S1144 (1999)

H. Fukuda 和 S. Kinoshita：“布里渊光谱观察到的液体中宏观量的耦合”J。