一种直接数据采集的太赫兹时域光谱快速扫描系统研究  

Research on a rapid scanning system of terahertz time domain spectroscopy by direct data acquisition

作　　者：徐咏 邱亮 古东才 彭建盛[1] XU Yong;QIU Liang;GU Dongcai;PENG Jiansheng(School of Artificial Intelligence and Smart Manufacturing,Hechi University,Hechi 546300,China;School of Optical-Electrical and Computer Engineering,Univercity of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]河池学院人工智能与制造学院人工智能与信息处理重点实验室,广西河池546300 [2]上海理工大学光电信息与计算机工程学院太赫兹技术研究院,上海200093

出　　处：《光学技术》2022年第6期703-709,共7页Optical Technique

基　　金：国家自然科学基金项目(62063006);河池学院校级科研项目(2022YLXK003)。

摘　　要：针对太赫兹时域光谱仪的国产化、高性能和灵活便携要求,分析了微弱太赫兹脉冲信号的顺序等效采样原理,设计了用于太赫兹光电导探测的高速直接数据采集系统,提出一种由飞秒脉冲激光器、电动光学延迟线、太赫兹光电导天线、直接数据采集系统、三轴位移平台、半导体制冷温控器和PC计算机组成的直采式太赫兹时域光谱快速扫描系统,最后进行系统测试和分析。实验结果表明,在相同的空载测试条件下,系统比传统SR830锁相放大系统的信号频域动态范围提高了9dB、有效频谱宽度提高了0.4THz,经过512次时域平均后系统信号频谱动态范围超过72dB、有效频谱宽度高达3.5THz。Aiming at the requirements of localization,high performance and flexibility and portability of terahertz time-domain spectrometers,the principle of sequential equivalent sampling of weak terahertz pulse signals is analyzed,and a high-speed direct data acquisition system for terahertz photoconductive detection is designed.A direct-acquisition terahertz time-domain spectroscopy fast scanning system composed of femtosecond pulsed lasers,motorized optical delay lines,terahertz photoconductive antennas,direct data acquisition systems,three-axis displacement platforms,semiconductor refrigeration thermostats and PC computers.Finally,the system is tested and analyzed.The experimental results show that,under the same no-load test conditions,the system has a 9 dB increase in the frequency domain dynamic range of the signal compared to the traditional SR830 lock-in amplifier system,and a 0.4 THz increase in the effective spectrum width.After 512 times of time domain averaging,the system signal spectrum is the dynamic range exceeds 72 dB and the effective spectral width is up to 3.5 THz.

关 键 词：赫兹时域光谱 直接数据采集 顺序等效采样 快速扫描 模数转换 

分 类 号：TN29[电子电信—物理电子学]