Real-time absolute frequency measurement of continuous-wave terahertz radiation based on dual terahertz combs of photocarriers with different frequency spacings.
Real-time absolute frequency measurement of continuous-wave terahertz radiation based on dual terahertz combs of photocarriers with different frequency spacings.
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DOI：
10.1364/oe.23.011367
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发表时间：
2015-01
期刊：
影响因子：
3.8
通讯作者：
T. Yasui;Kenta Hayashi;R. Ichikawa;H. Cahyadi;Y. Hsieh;Y. Mizutani;Hirotsugu Yamamoto;T. Iwata;H. Inaba;K. Minoshima
中科院分区：
文献类型：
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作者：
T. Yasui;Kenta Hayashi;R. Ichikawa;H. Cahyadi;Y. Hsieh;Y. Mizutani;Hirotsugu Yamamoto;T. Iwata;H. Inaba;K. Minoshima
实时测量连续波太赫兹(CW-THz)辐射的绝对频率是实际CW-THz源的表征和频率校准所必需的。提出了一种实时监测连续太赫兹辐射绝对频率的方法，即基于不同频率间隔的双太赫兹光载流子梳同时测量两对拍频和激光重复频率。为了验证该方法，采用基于双飞秒激光器的双结构构建了以太赫兹梳状为基准的频谱分析仪。无论PC-THz梳子中是否有频率控制，在100赫兹的测量速率下，频率精度都达到了10(-11)。此外，实时准确地监测了跨越PC-THz梳子的几种模式的CW-THz频率的大波动。该方法将为实际CW-THz源的研究和开发以及其他应用提供有力的工具。
Real-time measurement of the absolute frequency of continuous-wave terahertz (CW-THz) radiation is required for characterization and frequency calibration of practical CW-THz sources. We proposed a method for real-time monitoring of the absolute frequency of CW-THz radiation involving temporally parallel, i.e., simultaneous, measurement of two pairs of beat frequencies and laser repetition frequencies based on dual THz combs of photocarriers (PC-THz combs) with different frequency spacings. To demonstrate the method, THz-comb-referenced spectrum analyzers were constructed with a dual configuration based on dual femtosecond lasers. Regardless of the presence or absence of frequency control in the PC-THz combs, a frequency precision of 10(-11) was achieved at a measurement rate of 100 Hz. Furthermore, large fluctuation of the CW-THz frequencies, crossing several modes of the PC-THz combs, was correctly monitored in real time. The proposed method will be a powerful tool for the research and development of practical CW-THz sources, and other applications.