Enhanced tunable narrow-band THz emission from laser-modulated electron beams
Enhanced tunable narrow-band THz emission from laser-modulated electron beams
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DOI：
10.1103/physrevstab.12.080701
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发表时间：
2009-06
影响因子：
--
通讯作者：
D. Xiang;G. Stupakov
中科院分区：
文献类型：
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作者：
D. Xiang;G. Stupakov
提出并分析了一种利用激光调制电子束对激光频率进行下变频以产生增强型窄带太赫兹辐射的方案。在该方案中，电子束首先由波数分别为k{sub 1}和k2的两个激光器进行能量调制。在通过色散部分之后，能量调制被转换为密度调制。由于非线性转换过程，光束将在波数k = nk{sub 1} + m {sub 2}处具有密度调制，其中n和m是正整数或负整数。通过适当地选择激光器和色散部分的参数，可以使用光学激光器在光束中产生太赫兹频率的密度调制。这种密度调制光束可以用来产生强大的窄带太赫兹辐射。由于太赫兹辐射与激光器是紧密同步的，它应该为光泵太赫兹探测实验提供高的时间分辨率。太赫兹辐射的中心频率可以通过改变两个激光器的波长和电子束的能量啁啾来容易地调谐。所提出的方案在原理上能够产生覆盖整个THz范围的强窄带THz辐射，并且为可调谐强窄带THz源提供了一种有希望的方法。«少
We propose and analyze a scheme to generate enhanced narrow-band terahertz (THz) radiation through down-conversion of the frequency of optical lasers using laser-modulated electron beams. In the scheme the electron beam is first energy modulated by two lasers with wave numbers k{sub 1} and k2, respectively. After passing through a dispersion section, the energy modulation is converted to density modulation. Due to the nonlinear conversion process, the beam will have density modulation at wave number k = nk{sub 1} + mk{sub 2}, where n and m are positive or negative integers. By properly choosing the parameters for the lasers and dispersion section, one can generate density modulation at THz frequency in the beam using optical lasers. This density-modulated beam can be used to generate powerful narrow-band THz radiation. Since the THz radiation is in tight synchronization with the lasers, it should provide a high temporal resolution for the optical-pump THz-probe experiments. The central frequency of the THz radiation can be easily tuned by varying the wavelength of the two lasers and the energy chirp of the electron beam. The proposed scheme is in principle able to generate intense narrow-band THz radiation covering the whole THz range and offers a promisingmore » way towards the tunable intense narrow-band THz sources.« less