干涉法测量连续太赫兹波频谱

Continuous Terahertz Spectrum Measurement Based on Interferometry

描述了一种基于惠特曼干涉理论,采用步进扫描方式工作的连续太赫兹波频谱测量方法。对所提出的连续太赫兹波频谱测量方法进行了理论分析,并用计算机对频谱及能量密度分布进行实时采集。根据该方法搭建测量光路采集太赫兹波频谱及能量密度数据。将实验数据与理论计算数据进行比较,得到了良好的一致性结果。采用镀银反射镜、热释电探测器与斩波器构建测量光路,对干涉强度进行单点探测,利用扫描步进方式获得了频率为210 GHz连续式太赫兹波源返波振荡器(BWO)及400 GHz耿氏振荡器的频谱和能量密度分布,测量精度为1 GHz。结果表明,采用此干涉方法可以准确测量连续式太赫兹波源的频谱及能量密度分布,为今后实现太赫兹波段成像等领域的应用提供了有力的支持。

A method of measuring continuous terahertz frequency spectrum is provided based on Whitman interference theory effect and step-scanned working mode. The continuous terahertz spectrum measurement is calculated theoretically, and the spectrum and the energy density are taken by the computer. The measuring optical structure is set up to obtain the data of terahertz frequency-spectrum and energy density distribution. The measuring data accord well with that of theoretical analysis. The silvering reflect mirror,pyroelectric detector and chopper are used to build the measuring optical path to detect the interference intensity of one point. Frequency spectrum and energy density distribution of 210 GHz continuous terahertz backward-wave oscillator（BWO） and 400 GHz Gunn oscillator are obtained by step-scanned working mode. The accuracy of this measurement is 1 GHz. These results show that, using this method the frequency spectrum and energy density distribution of continuous terahertz wave source can be measured accurately. It provides a strong support for terahertz wave imaging research.