太赫兹时域光谱技术在流体包裹体研究中的应用

Application of Terahertz Time-Domain Spectroscopy in Fluid Inclusion Study

流体包裹体是研究矿物晶体演化的重要手段之一,它能反映矿物演化最原始的信息(温度、压力、pH值等)。在演化过程中,温度压力等外界因素直接影响包裹体的数量和大小,从而影响晶体的各种性质。本文利用太赫兹时域光谱系统(THz-TDS),对不同生长温度下KCl晶体内部的包裹体进行了检测,得到了样品的时域、频域和吸收系数曲线,并通过显微镜观察、计算得到了样品内部包裹体的面积,建立了包裹体面积和吸收系数的对应关系模型。通过对样品的吸收系数和样品内部包裹体面积的对比,可以看出二者具有相同的变化趋势,即晶体内部包裹体面积越大,THz吸收系数越大,说明THz吸收系数可以反映不同生长温度的晶体内部包裹体面积的变化情况,解析包裹体面积对太赫兹光学参数的影响,为流体包裹体的研究提供了一种新的有效途径。该研究创新点在于利用THz-TDS快速检测晶体内部包裹体面积的变化情况,说明了太赫兹技术完全可以用于包裹体的研究中,为包裹体的研究提供了一种全新的快速、无损的检测方法。

Fluid inclusion is one of the most important methods to study the evolution of mineral crystals ,which can reflect the original information of mineral evolution （temperature ,pressure ,pH ,etc） .The external factors ,such as temperature and pres-sure in the process of evolutiondirectly affect the quantity and size of inclusions ,w hich are related to the properties of crystals . In this paper ,terahertz time-domain spectroscopy was used to detect KCl crystals with different growth temperature ,and the curves of time domain ,frequency domain and absorption coefficient were obtained .In addition ,microscope was used to observe the inclusions inside samples .The results showed that there was a corresponding relationship between the absorption coefficient and the area of the inclusions .The larger the area of inclusions was ,the more coefficient the THz absorption was ,and the anal-ysis of the influence of the area of inclusions on terahertz optical parameters provided a new and effective way for the study of flu-id inclusions .The innovation of this paper is to use THz-TDS to quickly detect the change of the area of inclusions in crystals . The results indicates that terahertz time domain spectroscopy ,as a new nondestructive testing method ,has a unique advantage in the detection of inclusions .