Detection of transient low frequency mode by time-resolved far-infrared spectroscopy with a coherent radiation.

通过具有相干辐射的时间分辨远红外光谱检测瞬态低频模式。

• 批准号: 04555009
• 负责人: KONDO Yasuhiro
• 金额: $ 5.82万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research (B)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-04555009/
• 关键词: Time-resolved spectroscopy; far-infrared; transient absorption; coherent radiation; synchrotron radiation; multichannel detector; array detector; 放射光; 遠赤外分光; マルチャンネル検出器; 加速器; アルカリハライド; 緩和励起子

Recent research in Tohoku University revealed that a high energy electron pulse generates intense far-infrared radiation when it passes through magnetic field or thin metal foils. This radiation is an intense CW radiation ranging 30 -40 cm^<-1> with a time width of less than several ps, suggesting that it can be used as a probe light for the transient absorption spectroscopy. In alkali halide crystals, electronic excitation induces defect formation due to recombination of a self-trapped exciton, STE.A recent research using ps laser photolysis has suggested that the STE in NaCl may have the low-frequency vibration which is infrared active.The aim of this project is (1) to build a system for the far-infrared transient spectroscopy, (2) to detect the low-frequency mode, and (3) to detect THz radiation from laser-excited semiconductor suefaces. In this system, a crystal is excited by the electron pulses and the induced transient states are probed by the far-infrared pulses which was genera … More ted by the electron pulses. For this purpose we make a ten-channel far-infrared polychromator-detector by which the induced absorption spectrum can be measured with single electron pulse.Results :(1). A 10-channel polychromator-detector consists of ten InSb hot-electron bolometers and concave gratings were built. This polychromator-detector can detect far-infrared radiation ranging from 4 to 30 cm^<-1>. The detector performance for the pulsed radiation was confirmed by using 300 MeV linac in Tohoku University. For cw far-infrared radiation, a ten-channel lock-in amplifier was made by this project.(2). The transient absorption measurements were made on several NaCl single crystals at LHeT.However, measured transient spectra showed no definite absorption band due to the low-frequency mode.(3). By using this system, far-infrared radiation from a fs-laser pulse irradiated GaAs crystal surface was also measured. The dependence of the radiation on the incident angle, polarization, and the intensity of the fs laser pulses were determined. Less

Tohoku大学的最新研究表明，高能电子脉冲通过磁场或薄金属箔时会产生强烈的远红外辐射。该辐射是一种强烈的CW辐射，范围为30 -40 cm^<-1>，时间宽度小于几个PS，这表明它可以用作瞬态抽象光谱的探针光。在碱性卤化物晶体中，电子兴奋会导致由于自我捕获的兴奋的重组而引起的缺陷形成，Ste.Se.ASTE.A的最新研究表明，NACL中NACL中的Ste Ste Ste在NACL中具有低频振动，可能是高频振动，这是该项目的高度启动。 （3）从激光兴奋的半导体suefaces中检测辐射。在该系统中，晶体受到电子脉冲的激发，诱导的瞬态状态是由远红外的脉冲探测的，远红外脉冲是属的……更由电子脉冲探测。为此，我们制作一个十通道远红外的多晶仪检测器，可以通过单个电子脉冲来测量诱导的抽象光谱：（1）。一个10通道的多晶仪检测器由十个INSB热电子验光仪和凹面光栅组成。该多重晶状体检测器可以检测到4至30 cm^<-1>的远红外辐射。通过在Tohoku大学使用300 MEV LINAC确认了脉冲辐射的检测器性能。对于CW远红外辐射，该项目制作了一个十通道锁定放大器。（2）。瞬态吸收测量是在LHET的几个NaCl单晶上进行的。但是，测得的瞬态光谱显示出由于低频模式而没有确定的吸收带。（3）。通过使用该系统，还测量了来自FS激光脉冲辐照的GAAS晶体表面的远红外辐射。确定了辐射对入射角，极化和FS激光脉冲的强度的依赖性。较少的

项目成果

YASUHIRO KONDO: "Far-Infrared Pulse Radiolysis by Using a Coherent Synchrotron Radiation (I)" Research Report of Laboratory of Nuclear Science, Tohoku University. Vol 25. 131-135 (1992)

Yasuhiro KONDO：“使用相干同步辐射的远红外脉冲辐射分解（I）”东北大学核科学实验室的研究报告。

YASUHIRO KONDO: "Detection of Coherent Radiation by a Multichannel Far-Infrared Array Detector" Research Report of Laboratory of Nuclear Science, Tohoku University. Vol 26. 323-329 (1993)

Yasuhiro KONDO：“多通道远红外阵列探测器检测相干辐射”东北大学核科学实验室研究报告。

近藤泰洋: "コヒーレント放射光による遠赤外パルスラジオリシス" 核理研研究報告. 25. 131-135 (1992)

Yasuhiro Kondo：“使用相干同步加速器辐射的远红外脉冲放射分解”RIKEN 研究报告。25. 131-135 (1992)。

近藤泰洋: "多チャンネル配列検出器による遠赤外パルスラジオリシス" 核理研研究報告. 27. 15-21 (1994)

Yasuhiro Kondo：“使用多通道阵列检测器的远红外脉冲放射分解”RIKEN 研究报告。27. 15-21 (1994)。

中里俊晴: "コヒーレント放射によるバンチ長計測(I)" 核理研研究報告. 26. 297-303 (1993)

Toshiharu Nakazato：“相干辐射束长度测量 (I)” RIKEN 研究报告 26. 297-303 (1993)。