Highly precise and accurate terahertz polarization measurements based on electro-optic sampling with polarization modulation of probe pulses
Highly precise and accurate terahertz polarization measurements based on electro-optic sampling with polarization modulation of probe pulses
复制标题
DOI：
10.1364/oe.22.017915
复制
发表时间：
2014-07-28
期刊：
影响因子：
3.8
通讯作者：
Kuwata-Gonokami, Makoto
中科院分区：
文献类型：
--
作者：
Nemoto, Natsuki;Higuchi, Takuya;Kuwata-Gonokami, Makoto
我们已经开发了一种电光（EO）采样方法与偏振调制的探测脉冲，这种方法使我们能够测量的太赫兹（THz）电场矢量的方向与精度为0.1 mrad的数据采集时间为660 ms，使用14.0 kHz的重复率脉冲光源。结合太赫兹时域光谱技术，得到了二维太赫兹电场随时间的变化。我们使用光弹调制器进行探针偏振调制，并使用（111）取向的氧化锌晶体作为电光晶体。采用倾斜脉冲前沿激发法和稳定的再生放大脉冲，制备了稳定、强的THz脉冲，并对信号进行了逐脉冲的模数转换。这些技术大大减少了统计误差，使亚mrad太赫兹偏振测量。我们检查了这种方法的性能，通过测量作为样品的线栅偏振器。该方法为高精度太赫兹偏振敏感测量开辟了新的领域。(C)2014年美国光学学会
We have developed an electro-optic (EO) sampling method with polarization modulation of probe pulses; this method allows us to measure the direction of a terahertz (THz) electric-field vector with a precision of 0.1 mrad in a data acquisition time of 660 ms using a 14.0-kHz repetition rate pulsed light source. Through combination with a THz time-domain spectroscopy technique, a time-dependent two-dimensional THz electric field was obtained. We used a photoelastic modulator for probe-polarization modulation and a (111)-oriented zincblende crystal as the EO crystal. Using the tilted pulse front excitation method with stable regeneratively amplified pulses, we prepared stable and intense THz pulses and performed pulse-by-pulse analog-to-digital conversion of the signals. These techniques significantly reduced statistical errors and enabled sub-mrad THz polarization measurements. We examined the performance of this method by measuring a wire-grid polarizer as a sample. The present method will open a new frontier of high-precision THz polarization sensitive measurements. (C) 2014 Optical Society of America