共查询到19条相似文献,搜索用时 156 毫秒
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黎明 杨兴繁 许州 束小建 鲁向阳 黄文会 王汉斌 窦玉焕 沈旭明 单李军 邓德荣 徐勇 柏伟 冯第超 吴岱 肖德鑫 王建新 罗星 周奎 劳成龙 闫陇刚 林司芬 张鹏 张浩 和天慧 潘清 李相坤 李鹏 刘宇 杨林德 刘婕 张德敏 李凯 陈亚男 《物理学报》2018,67(8):84102-084102
中国工程物理研究院基于半导体光阴极高压直流电子枪和超导直线加速器的高平均功率太赫兹自由电子激光达到了受激饱和,并实现了太赫兹光输出频率可调.在1.99,2.41和2.92 THz三个频率点上进行测试,测得太赫兹宏脉冲内平均功率大于10 W,最高达17.9 W.本文介绍了太赫兹自由电子激光装置的主要组成部分及受激饱和实验的结果. 相似文献
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基于汤姆逊背散射的激光丝扫描(LW)方法作为无阻拦电子横向尺寸测量手段,近年来广泛应用于高能对撞机和能量回收环直线加速器。为在连续模式下测量高平均功率相干强太赫兹源的直流光阴极电子枪(DC-gun)电子束横向束斑,本文提出了一种基于驱动激光器分束的高重复频率,较低脉冲功率的新型LW系统。通过理论及模拟分析,证明该系统相对于常规LW系统具有成本低、精度高、探测时间短、对电子束影响小的优势,并给出了用于自由电子激光太赫兹(FEL-THz)装置DC-gun出口电子束LW系统的实验设计。 相似文献
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磷化铟(InP)属于Ⅲ-Ⅴ族化合物半导体材料, 在毫米波的应用中展示出了高性能,在非线性太赫兹器件应用上具有很大的潜力。以前关于InP的研究主要集中于太赫兹频率在0.1~4 THz的频率范围内,在4~10 THz频率范围内InP的太赫兹光学数据还是空白。该研究利用空气等离子体相干探测太赫兹波的时域光谱系统研究了无掺杂的InP晶片在超宽THz频率范围(0.5~18 THz)内的光学特性, 实验中用电离的空气作为太赫兹的发射器和探测器, 利用可以调制的局部偏压诱导二次谐波产生,使在气体中太赫兹波的相干探测成为可能,明显提高了系统的动态范围和灵敏度。产生的太赫兹频谱宽度主要被激光脉冲持续时间所限制,太赫兹脉冲通过InP晶片后相对于参考脉冲会延迟,同时振幅会降低。另外,太赫兹信号的频谱振幅在6.7~12.1 THz范围内下降到本底噪声。同时还可以看出InP晶片在6.7~12.1 THz频率范围内不透光,在0.8~6.7 THz以及12.1~18 THz频率范围内InP的吸收系数相对较低,特别是在15~17.5 THz范围内吸收系数很低并且保持相对稳定,与此同时它的折射率单调增加。这些发现将有助于基于InP晶片的非线性太赫兹器件设计。 相似文献
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采用一个光谱匹配的太赫兹(THz)量子阱探测器(QWP)研究了一激射频率约为41 THz的THz量子级联激光器(QCL)在不同驱动电流下的发射谱,分析了测量得到的发射谱谱型和谱峰位置,根据测量的发射谱估算了太赫兹量子级联激光器发射功率随驱动电流变化的情况,从而得到了THz QCL激射的电流密度范围及其阈值电流密度.文中还研究了THz QWP在不同温度下对THz QCL 激光辐射的响应特性.研究结果表明,THz QWP在表征THz QCL的发射谱方面是一种很好的探测器,并有望成为未来THz通信中的接收装置.
关键词:
太赫兹量子阱探测器
太赫兹量子级联激光器
太赫兹通信
Fourier变换红外光谱 相似文献
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针对中物院高功率太赫兹自由电子激光(THz FEL)装置,结合FEL光腔振荡器实验的实际情况,提出了全波导近共心谐振腔设计方案。完成了THz波段波导光腔对光腔品质影响的理论分析和模拟计算,确定了波导设计尺寸为14 mm和22 mm。同时针对最初实验调试过程中无法出光饱和的问题,提出将波导更换为22 mm大尺寸波导的建议,波导更换后很快在2.56 THz获得饱和出光。另外针对实验频段无法覆盖到1~2 THz的问题,我们通过波导内壁粗糙度进行分析判断,提出采用14 mm铜材质的全波导FEL振荡器的设计方案,采用该方案后,实验成功将辐射频段拓展到0.7~4.2 THz,获得饱和输出。 相似文献
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The experimental result of terahertz (THz) coherent transition radiation generated from an ultrashort electron bunching beam is reported.During this experiment,the window for THz transmission from ultrahigh vacuum to free air is tested.The compact measurement system which can simultaneously test the THz wave power and frequency is built and proofed.With the help of improved Martin-Puplett interferometer and Kramers-Krong transform,the longitudinal bunch length is measured.The results show that the peak power of THz radiation wave is more than 80 kW,and its radiation frequency is from 0.1 THz to 1.5 THz. 相似文献
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Yu. H. Avetisyan A. H. Makaryan V. R. Tadevosyan K. L. Vodopyanov 《Journal of Contemporary Physics (Armenian Academy of Sciences)》2009,44(4):161-167
Generation of terahertz (THz) radiation by nonlinear mixing of laser frequencies in GaAs crystal is considered for the case of free and guided propagation of THz waves. In the first case the strong diffraction of the THz radiation leads to the deviation from the known square-law growth of the generator power with increasing crystal length, In the second case the spatial divergence of the exciting laser beam results in the appearance of a maximum in the generated power dependence on the radius of the nonlinear waveguide. According to estimations, the optimal radius of the laser beam is 18 μm for the waveguide length of 6 mm and the maximal generated THz power is ~27 W at the laser beam power of 10 kW. 相似文献
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We report the generation of tunable, narrow-band, few-cycle and multicycle coherent terahertz (THz) pulses from a temporally modulated relativistic electron beam. We demonstrate that the frequency of the THz radiation and the number of the oscillation cycles of the THz electric field can be tuned by changing the modulation period of the electron beam through a temporally shaped photocathode drive laser. The central frequency of the THz spectrum is tunable from ~0.26 to 2.6 THz with a bandwidth of ~0.16 THz. 相似文献
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密度高、成像分辨率高、成像速度快的X射线数字成像检测需要高能微焦点大剂量X射线源,高品质电子源是实现这一X射线源的关键手段。基于中国工程物理研究院太赫兹自由电子激光的主加速器,验证了低发射度、低能散度的高亮度电子束实现高能微焦点的可行性,得到电子束半高全宽尺寸小于70μm的9 MeV微焦点,并初步开展成像实验,双丝像质计焦斑清晰分辨9D号丝,丝直径0.13 mm。 相似文献
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On the basis of an energy-recovery linac, a terahertz source with a potential for kilowatts of average power is proposed in Shanghai, which will serve as an effective tool for material and biological sciences. In this paper, the physical design of two free electron laser (FEL) oscillators, in a frequency range of 2--10 THz and 0.5--2 THz respectively, are presented. By using three-dimensional, time-dependent numerical modeling of GENESIS in combination with a paraxial optical propagation code, the THz oscillator performance, the detuning effects, and the tolerance requirements on the electron beam, the undulator field and the cavity alignment are given. 相似文献
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在众多实现太赫兹辐射的方法中, 非线性光学共线差频能够实现高功率、宽波段、连续可调谐的太赫兹波辐射. 理论分析表明, 各向同性磷化镓晶体, 在1064 nm附近波长激光共线差频下具有毫米量级的相干长度, 能够满足高功率宽波段的太赫兹辐射条件.实验证明, 磷化镓晶体共线差频实现高功率宽波段的太赫兹光辐射, 其太赫兹光波长调谐范围为95.9–773.4 μm (0.39–3.13 THz), 最高峰值功率7 W位于频率2.0 THz处.该实验结果与理论计算基本保持一致.
关键词:
太赫兹源
磷化镓
共线差频 相似文献
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One-dimensional particle-in-cell (PIC) program is used to simulate the generation of high power terahertz (THz) emission from the interaction of an ultrashort intense laser pulse with underdense plasma. The spectra of THz radiation are discussed under different laser intensity, pulse width, incident angle and density scale length. High-amplitude electron plasma wave driven by a laser wakefield can produce powerful THz emission through linear mode conversion under certain conditions. With incident laser intensity of 1018 W/cm2, the generated emission is computed to be of the order of several MV/cm field and tens of MW level power. The corresponding energy conversion efficiency is several ten thousandths, which is higher then the efficiency of other THz source and suitable for the studies of THz nonlinear physics. 相似文献
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利用热力学统计理论和激光器输出特性理论,建立了太赫兹量子级联激光器(THz QCL)有源区中上激发态电子往更高能级电子态泄漏的计算模型,以输出功率度量电子泄漏程度研究分析了晶格温度和量子阱势垒高度对电子泄漏的影响.数值仿真结果表明,晶格温度上升会加剧电子泄漏,并且电子从上激发态泄漏到束缚态的数量大于泄漏到阱外连续态,同时温度的上升也会降低激光输出功率.增加量子阱势垒高度能抑制电子泄漏,并且有源区量子阱结构中存在一个最优量子阱势垒高度. THz QCL经过最优量子阱势垒高度优化后,工作温度得到提升,其输出功率相比于以往的结果也有所提高.研究结果对优化THz QCL有源区结构、抑制电子泄漏和改善激光器输出特性有指导作用. 相似文献
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We propose an optically pumped nonpolar GaN/AlGaN quantum well (QW) active region design for terahertz (THz) lasing in the wavelength range of 30 μm~ 40 μm and operating at room temperature. The fast longitudinal optical (LO) phonon scattering in GaN/AlGaN QWs is used to depopulate the lower laser state, and more importantly, the large LO phonon energy is utilized to reduce the thermal population of the lasing states at high temperatures. The influences of temperature and pump intensity on gain and electron densities are investigated. Based on our simulations, we predict that with a sufficiently high pump intensity, a room temperature operated THz laser using a nonpolar GaN/AlGaN structure is realizable. 相似文献