宽带太赫兹波光束轮廓和频率分布特性(英文)

Beam profile and frequency distribution characterization of broadband terahertz wave

利用刀口法在透射式太赫兹时域光谱系统中对脉冲太赫兹波的光束轮廓和能量的轴向分布进行测量.通过快速傅里叶变换,可以获得太赫兹脉冲的频率分布.实验结果显示,脉冲太赫兹光斑的能量符合高斯分布.实验测量到的太赫兹光斑大小与理论基本吻合,证明刀口法可用于宽带激光光束测量.该结果为太赫兹成像以及太赫兹技术在其他领域的应用奠定了基础.

Beam profile and axial intensity-distribution of pulse terahertz （THz） wave were measured by the knifeedge method in a transmission-type THz time domain spectroscopy system. By fast-Fourier-transform, the frequency distribution of pulse THz wave could also be obtained. The results show that the intensity of the pulse THz beam fits the Gaussian distribution. The size of the measured THz spot is nearly in agreement with the theoretical analysis, which proved that the knife-edge method can be used to characterize the beam profile of broadband laser beam. This work will also provide the experimental data for THz imaging technology.