Zheng Shuiqing, Pan Xinjian, Cai Yi, Lin Qinggang, Li Ying, Xu Shixiang, Li Jingzhen, Fan Dianyuan
Opt Lett. 2017 Nov 1;42(21):4263-4266. doi: 10.1364/OL.42.004263.
We propose a common-path spectral interferometer for single-shot terahertz (THz) electro-optics (EO) detection, where a probe pulse pair with orthogonal polarizations and a relative time delay are generated by simply using a birefringent plate. One of them, as the object, transmits through a THz EO crystal with THz phase modulation, while the other goes through the crystal without any phase imposed by target the THz field as the reference. The co-axial propagation of the pulse pair can effectively reduce the noises due to mechanical vibrations, air turbulences, and temperature fluctuations in the traditional non-common-path spectral interferometers. Our experiments show that, for a given target THz pulse field, the measured THz signals in a single-shot mode have a signal-to-noise ratio (SNR) of 41.2 with our THz common-path spectral interferometer, but 7.91 with a THz Mach-Zehnder spectral interferometer; thus, our design improves the SNR of the THz signal by about 5.2 times.
我们提出了一种用于单次太赫兹（THz）电光（EO）检测的共光路光谱干涉仪，其中通过简单地使用双折射板来产生具有正交偏振和相对时间延迟的探测脉冲对。其中一个脉冲作为探测对象，透过经过太赫兹相位调制的太赫兹电光晶体，而另一个脉冲则穿过该晶体，但不被目标太赫兹场施加任何相位，作为参考。脉冲对的同轴传播可以有效降低传统非共光路光谱干涉仪中由于机械振动、空气湍流和温度波动引起的噪声。我们的实验表明，对于给定的目标太赫兹脉冲场，使用我们的太赫兹共光路光谱干涉仪在单次模式下测量的太赫兹信号的信噪比（SNR）为41.2，而使用太赫兹马赫-曾德尔光谱干涉仪时为7.91；因此，我们的设计将太赫兹信号的信噪比提高了约5.2倍。
