报道了一种基于频率可调谐准高斯太赫兹波束的透射成像系统.研究表明,在这种成像系统中太赫兹波束具有良好的空间分布特性,其波束质量因子M2x=1.15,M2z=1.25,波束传输特性和聚焦特性良好.实验结果反映出成像系统的空间分辨能力与典型太赫兹波长(250μm)相接近.在太赫兹波输出1.0—2.5THz范围内,成像系统信噪比大于1000dB;在1.8THz处,信噪比大于6000dB.利用这种太赫兹波透射成像系统对样品进行了成像实验,并得到较为清晰的图像.
A terahertz wave imaging system based on the tunable terahertz source with the quasi-Gaussian beam output is reported.In this imaging system,terahertz wave beam is easy to be focused and transmitted owing its spatial distribution with the excellent beam quality factor of M2_x=1.15 and M2_z=1.25.The experimental results show the spatial resolving power of this imaging system is close to the typical terahertz wavelength of 250?μm.In the output range of 1.0—2.5?THz,the signal to noise ratio(SNR) is higher than 1000?dB,and the SNR is above 6000?dB at 1.8?THz.Based on this system,the terahertz imaging experiments for the several samples were performed,and clear pictures were obtained.