Amirkhan F, Robichaud A, Ropagnol X, Gratuze M, Ozaki T, Nabki F, Blanchard F
Opt Lett. 2020 Jul 1;45(13):3589-3592. doi: 10.1364/OL.393917.
The rapid growth of information technology is closely linked to our ability to modulate and demodulate a signal, whether in the frequency or in the time domain. Recent demonstrations of terahertz (THz) modulation involve active semiconductor metamaterial surfaces or use of a grating-based micromirror for frequency offset tuning. However, a wideband and active differentiator in the THz frequency band is yet to be demonstrated. Here, we propose a simple method to differentiate a THz pulse by inducing tiny phase changes on the THz beam path using a piezoelectric micromachined ultrasonic transducer array. We precisely demonstrate that the modulated THz signal detected after the piezoelectric device is proportional to the first-order derivative of the THz pulse. The proposed technique will be able to support a wide range of THz applications, such as peak detection schemes for telecommunication systems.
信息技术的快速发展与我们调制和解调信号的能力紧密相关，无论是在频域还是时域。最近关于太赫兹（THz）调制的演示涉及有源半导体超材料表面或使用基于光栅的微镜进行频率偏移调谐。然而，太赫兹频段的宽带有源微分器尚未得到证实。在此，我们提出一种简单的方法，通过使用压电微机械超声换能器阵列在太赫兹光束路径上引起微小的相位变化来对太赫兹脉冲进行微分。我们精确地证明了在压电装置之后检测到的调制太赫兹信号与太赫兹脉冲的一阶导数成正比。所提出的技术将能够支持广泛的太赫兹应用，例如电信系统的峰值检测方案。
