氢氧化铝的太赫兹特征峰及其增强技术

Terahertz Characteristic Peaks of Al（OH）3 and Techniques for Their Enhancement

利用太赫兹时域光谱技术测量了氧化铝和氢氧化铝样品在0.5~1.5THz范围内的太赫兹时域电场信号。对测量得到的时域信号进行了傅里叶变换,得到了样品信号与参考信号频域的振幅和相位信息。对比参考信号的频域谱发现,氢氧化铝在1.20THz和1.33THz处有明显的特征峰,而氧化铝与参考信号频域谱的特征峰相同。通过对石墨烯与氢氧化铝进行一定比例的掺杂,利用石墨烯表面等离激元的近场增强效应,增强了分子内羟基的共振伸缩,实现了对氢氧化铝特征峰的增强调控。这项研究不仅可以对氢氧化铝进行无损检测和有效识别,也可以利用石墨烯增加氢氧化铝的检测灵敏度,对进一步利用太赫兹时域光谱技术研究其他氢氧化物的光谱信息具有借鉴意义。

We measured the terahertz time-domain electric fields of alumina and aluminum hydroxide samples in the range of 0.5-1.5 THz using terahertz time-domain spectroscopy.The frequency-domain spectra of sample and reference signals containing the amplitude and phase information were obtained by the fast Fourier transform of the measured time-domain signals.Compared with the frequency-domain spectrum of a reference signal,one can find that the aluminum hydroxide sample has obvious characteristic peaks at 1.20 THz and 1.33 THz;however,the alumina samples have the same characteristic peaks as the reference signal.The near-field enhancement via the surface plasmon polaritons of graphene was used to enhance resonant stretching of the hydroxyl groups in a molecule by doping a certain proportion of graphene and aluminum hydroxide,and thereby the enhanced regulation of characteristic peaks of aluminum hydroxide is achieved.This study not only offers effective nondestructive test and identification of aluminum hydroxide,but also increases the detection sensitivity of aluminum hydroxide using graphene.Moreover,it has reference significance for further study of spectral information for other hydroxides using terahertz time-domain spectroscopy.