太赫兹科学与电子信息学报2026，Vol.24Issue(6)：692-700,9.DOI:10.11805/TKYDA2025301
太赫兹时域光谱仪非线性度校准方法
Calibration method for nonlinearity of terahertz time-domain spectrometer
摘要
Abstract
With the development of terahertz time-domain spectrometers toward a large dynamic range,the system's nonlinear response has become a core bottleneck limiting the accuracy of quantitative analysis.However,traditional nonlinearity calibration methods generally suffer from issues such as optical path interference(e.g.,bulk material attenuators are prone to causing wavefront distortion),bandwidth limitations,and difficulty in metrological traceability.These problems severely restrict the standardized application of terahertz time-domain spectrometers.To address the above challenges,this study develops an attenuator with low wavelength selectivity based on the skin effect to achieve nonlinearity calibration of terahertz time-domain spectrometers.The attenuator is an Inconel 600 alloy film.By establishing a complete calibration sequence with 7 attenuation levels and constructing a three-level metrological traceability chain of"terahertz source-standard power meter-attenuator",the accuracy and traceability of the calibration results are ensured.Calibration experiments were conducted at three characteristic frequency points:0.3 THz,0.9 THz,and 1.6 THz.The results show that the system's nonlinearity exhibits a trend of"first decreasing and then increasing"with frequency.The system exhibits the best performance in the mid-frequency band(0.9 THz),with nonlinearity as low as 1.5%.The nonlinearity is 3.2%in the low-frequency band(0.3 THz)and increases to 7.7%in the high-frequency band(1.6 THz).Moreover,the calibration results at all frequency points comply with metrological specifications.This method effectively avoids the inherent defects of traditional attenuators,provides a high-precision and traceable technical solution for the nonlinearity calibration of terahertz time-domain spectrometers.关键词
太赫兹时域光谱/非线性度校准/趋肤效应/Inconel 600合金/衰减器Key words
Terahertz Time-Domain Spectroscopy(THz-TDS)/nonlinearity calibration/skin effect/Inconel 600 alloy/attenuator分类
信息技术与安全科学引用本文复制引用
蔡高航,杨延召,吴斌,刘红元,王洪超,张集权,闫景开..太赫兹时域光谱仪非线性度校准方法[J].太赫兹科学与电子信息学报,2026,24(6):692-700,9.基金项目
国家重点研发计划资助项目(2023YFF0722400) （2023YFF0722400）
