植物油和动物脂肪在THz波段的吸收和色散

Absorption and dispersion of vegetable oil and animal fat in THz range

由超短激光脉冲产生的THz脉冲是具有较宽频带的电磁辐射,属于远红外波段,该波段电磁波与物质的相互作用是个崭新的研究领域.文章应用THz光谱技术研究了5种植物油和两种动物脂肪的THz光谱,得到了这些材料在0.2—1.6THz频率范围的折射率和吸收系数.结果表明,不同种类的油脂具有不同的折射率,其中植物油的折射率随频率的增加而略有降低,其值在1.46—1.66之间.吸收系数在0.2—1.2THz随频率的增加而增大.动物脂肪的折射率随频率变化基本不变,并且随温度升高而增大,其值在1.4—1.52之间.吸收系数在0.2—1.2THz随频率的增加而增大.该研究结果对于THz时域光谱技术应用于生物成像及生物医学有重要的意义.

Terahertz radiation generated by ultra short laser pulses has a broad band width in the far-infrared band. It is a new research field on terahertz wave interacting with materials, especially bio-materials. In this paper we studied five kinds of vegetable oil and two kinds of animal fats under different states using THz-TDS （THz time-domain spectroscopy ）. The refractive index and absorption coefficient of these materials are presented in the range from 0.2 to 1.6THz. The result shows that different oils have different refractive indices. The refractive indices of vegetable oils have a gentle decline and the refractive indices of animal fats increase with temperature. The coefficients of absorption also increase with frequency. It＇ s a meaningful result for the applications of biomedical sensing and imaging.