共查询到20条相似文献,搜索用时 10 毫秒
1.
V. S. Cherkassky B. A. Knyazev G. N. Kulipanov A. N. Matveenko P. D. Rudych N. A. Vinokurov 《Journal of Infrared, Millimeter and Terahertz Waves》2007,28(3):219-222
Though wire grid and strip polarizers are widely used for control of submillimeter radiation, both calculated and experimentally measured values of their transmission are often contradict one another. We have measured the transmission of wire and thin-film photolithographic polarizers at a wavelength of 0.13-mm using 100 W free electron laser radiation and compared the results with previous experiments and calculations. Using a thin-film photolithographic polarizer we showed that radiation of the Novosibirsk FEL after traveling through a 14-m beamline is plane-polarized with the degree of polarization better than 99.6%. 相似文献
2.
3.
太赫兹电磁波在材料表征、医学成像、无线通信、安全检测等领域有广泛的应用前景,是当前科学研究热点之一。基于自由电子与周期性光栅结构相互作用产生的Smith-Purcell辐射的Smith-Purcell自由电子激光凭借其易加工、可调谐、高功率等优点成为发展高功率太赫兹源的有效途径之一。本文对太赫兹Smith-Purcell自由电子激光的近期研究进展进行了综述,对基于特异Smith-Purcell辐射新型Smith-Purcell自由电子激光以及基于预群聚电子注的Smith-Purcell太赫兹源进行了着重介绍,这两类新型太赫兹自由电子激光结构克服了传统自由电子激光的若干缺点,有望发展为具有重要应用前景的紧凑型、大功率太赫兹源。 相似文献
4.
5.
6.
中物院太赫兹自由电子激光(CTFEL)装置是我国第一台基于超导加速器的高重复频率、高平均功率太赫兹自由电子激光装置。CTFEL利用光阴极直流高压电子枪和超导加速器产生约8 MeV电子束在波荡器中产生自发太赫兹(THz)辐射,并在光腔中受激放大获得饱和输出。得益于在0.7~4.2 THz频谱范围内连续可调以及平均功率大于10 W的特性,CTFEL为材料动力学、太赫兹成像、太赫兹生物学等领域提供了独特的研究平台。自2018年开放成为用户装置以来,每年提供不少于1000 h的稳定出光。未来CTFEL将在现有基础上升级成为红外太赫兹自由电子激光装置,实现太赫兹频率全覆盖以及最大功率大于100 W的目标,力争成为世界先进的长波长自由电子激光装置。 相似文献
7.
对国际上关于半导体太赫兹辐射源和太赫兹传输波导之间的耦合问题的研究进展和最新动态进行了较详细的分析和归纳总结.太赫兹频段是一个非常有科学价值电磁波频段,它在信息科学,天文学、医学、环境科学、国防等领域都有广阔的应用前景和应用价值.太赫兹的应用除了太赫兹辐射源,太赫兹传输器件,太赫兹探测器等关键器件之外,还必须解决太赫兹辐射源和太赫兹传输器件之间的耦合问题. 相似文献
8.
Nikolay Vinokurov 《Journal of Infrared, Millimeter and Terahertz Waves》2011,32(10):1123-1143
Free electron lasers (FEL) are the lasers which utilize the phenomenon of stimulated undulator radiation. Now they are the
most powerful sources of electromagnetic radiation with frequency tunable from 1 to 10 THz. Contrary to most lasers, motion
of an electron in the FEL may be described by classical mechanics and classical electrodynamics. Therefore they belong to
the family of vacuum electronic devices, such as traveling wave tubes or klystrons. The basics of the FEL physics are discussed.
General considerations are clarified through some examples. The Novosibirsk THz FEL is described briefly. 相似文献
9.
自由电子激光器的应用前景取决于器件能否小型化。本文对现有拉曼自由电子激光器的小型化进行了总体研究,以期实现台式拉曼自由电子激光器,还对自由电子激光器最终走向实用化具有现实意义。 相似文献
10.
杨晓东 《激光与光电子学进展》1998,35(4):8-13
空间光调制器(SLM)对我们还是一个比较陌生的名词,但它却正悄悄并稳步地进入我们的日常生活。空间光调制器又称光问,实质上是个随时间变化的挡板。光学十字开关便是它众多功能中的一例。它可看作由一组线性发光体列阵组成的栅,而由一组线性光探测器列阵组成另一个栅,两者互相垂直并隔一小段距离。每个发光体都能照到所有的探测器上。如上所述,这样一种光学十字开关似乎并不引起人们的兴趣。但如在发光体列阵与探测器列阵之间插入一挡板,只有板上能透光的部分可以将特定的发光体与选定的探测器连接。这个挡板就是空间光调制器。这… 相似文献
11.
12.
13.
Matthias Wichmann Markus Stein Arash Rahimi-Iman Stephan W. Koch Martin Koch 《Journal of Infrared, Millimeter and Terahertz Waves》2014,35(6-7):503-508
Michelson interferometry is used to investigate the pump-power dependent emission bandwidth of a THz emitter based on intra-cavity difference frequency generation in a two-color VECSEL. A multi-mode CW THz signal is found to result from the two simultaneously lasing groups of longitudinal VECSEL modes. Power-dependent experiments reveal a clear correlation between the THz signal bandwidth and the numbers of optical modes involved. 相似文献
14.
15.
Ming Chang Wang Chi Yang Byung Cheol Lee Jongmin Lee 《Journal of Infrared, Millimeter and Terahertz Waves》1999,20(10):1739-1748
A guided field is an important part for focusing the intense beam in Raman free electron laser. A new electron beam source with high brightness of 1012A/(m rad)2 based on a pseudospark discharge was developed [1]. Numerical simulation showed that the guided field for compact free electron lasers could be removed using the new beam source. An electron beam with 12 kA current and 300 kV voltage was obtained. Self-pinch effect of high current beam was observed, the beam propagates 75 cm with constant diameter of 1.5 mm without guided field. 相似文献
16.
Zongjun Shi Ziqiang Yang Zheng Liang 《Journal of Infrared, Millimeter and Terahertz Waves》2003,24(11):1823-1831
The dispersion characteristics of plasma–loaded free-electron laser has been analyzed using linear fluid model. The device under consideration consists of the cylindrical metallic waveguide, completely filled with background plasma and a relativistic electron beam which passes through a helical wiggler magnetic field. The result predicts that reasonable plasma density tends to improve the growth rate of the low-frequency optical wave of FEL and causes an shiftup in the operating frequency, However it has little effect on the growth rate of the high-frequency wave. In the plasma–loaded FEL, for the FEL oscillator, it may be tuned by varying the plasma density; and for the FEL amplifier, the wider frequency bandwidth is gained. A critical density n c p for the background plasma density is found. 相似文献
17.
18.
19.
20.
由于太赫兹辐射的独特性质和潜在的应用价值, 国内外关于太赫兹波的产生和探测的研究正呈现日益繁荣的景象, 目前太赫兹相干辐射源的研究已成为太赫兹技术领域最重要的前沿课题之一。介绍了产生太赫兹相干辐射的三种主要途径:一是光学技术, 它从高频向低频发展, 其代表为太赫兹激光器, 如气体激光器、半导体激光器和量子级联激光器等; 二是电子学技术, 它由低频向高频发展, 如微波管、固体微波源等; 三是光电子技术, 其频率由1 THz向两侧展宽, 采用超快激光脉冲触发产生太赫兹脉冲。设计了基于光学技术的太赫兹相干辐射系统, 该装置根据气体振转能级跃迁原理, 采用高压直流激励方式产生受激辐射, 波导管谐振腔体, 工作气体为N2, CD4和D2, 经过优化设计, 预计可以产生1.54 THz和1.58 THz的波连续输出。 相似文献