On-chip coherent frequency-domain THz spectroscopy for electrical transport
On-chip coherent frequency-domain THz spectroscopy for electrical transport
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DOI：
10.1063/5.0024089
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发表时间：
2020-10-19
影响因子：
4
通讯作者：
Hashisaka, Masayuki
中科院分区：
文献类型：
--
作者：
Yoshioka, Katsumasa;Kumada, Norio;Hashisaka, Masayuki
基于连续波激光光谱学，在200 MHz ~ 1.6 THz超频范围内的共面波导上开发了一种相干频域太赫兹（THz）光谱技术。通过混合两个频率可调的连续波激光器产生的光脉冲聚焦在光导开关上，以产生和检测太赫兹电路中的高频电流。与时域光谱学相比，我们的频域光谱学可以实现前所未有的10 MHz频率分辨率，而无需使用飞秒激光光学的复杂构建块。此外，由于光混合技术的相干性，我们能够使用希尔伯特分析和傅里叶反变换在时域中识别多重反射的起源。这些结果表明，片上相干频域谱的宽带、频率分辨率、可用性和时域可及性等优势，为测量集成太赫兹电路中的超快电子输运提供了独特的能力。
We developed a coherent frequency-domain terahertz (THz) spectroscopic technique on a coplanar waveguide in the ultrabroad frequency range from 200 MHz to 1.6 THz based on continuous wave (CW) laser spectroscopy. Optical beating created by mixing two frequency-tunable CW lasers is focused on photoconductive switches to generate and detect high-frequency current in a THz circuit. In contrast to time-domain spectroscopy, our frequency-domain spectroscopy enables an unprecedented frequency resolution of 10 MHz without using the complex building blocks of femtosecond laser optics. Furthermore, due to the coherent nature of the photomixing technique, we are able to identify the origin of multiple reflections in the time domain using the Hilbert analysis and inverse Fourier transform. These results demonstrate that the advantages of on-chip coherent frequency-domain spectroscopy, such as its broadband, frequency resolution, usability, and time-domain accessibility, provide a unique capability for measuring ultrafast electron transport in integrated THz circuits.