生物基底材料的超宽频带太赫兹光谱研究

发布时间：2019-04-25 22:32

【摘要】：作为一种新兴的方式,太赫兹时域光谱和成像已经被广泛应用到研究不同生物组织的光学特性。在空气等离子体处施加偏置电场对太赫兹波脉冲进行外差式相干检测(air-biased-coherent-detection,ABCD)的太赫兹系统具有超宽频带和可以在较远距离进行成像的优点,十分适用于对生物组织进行超宽谱研究,而对生物组织进行光谱测量通常需要基底材料。利用太赫兹ABCD系统对四种典型的基底材料(石英,高密度聚乙烯,聚四氟乙烯和石蜡)的光学参数进行测定,并计算其在1~15THz频率范围内的吸收系数和折射率。结果表明,高密度聚乙烯和石蜡可以很好的被用作生物组织超宽频带太赫兹光谱测量的基底材料。同时,虽然石英和聚四氟乙烯都是窄带(0.1~3THz)太赫兹系统中常用的基底材料,但是由于它们在高于5THz的频率范围内对太赫兹波具有较强的吸收,所以不能用作超宽频带太赫兹光谱测量的基底材料。
[Abstract]:As a new method, terahertz time domain spectroscopy and imaging have been widely used to study the optical properties of different biological tissues. The terahertz system with bias electric field applied to terahertz pulse for heterodyne coherent detection (air-biased-coherent-detection,ABCD) has the advantages of ultra-wide band and can be used for imaging in a long distance. It is very suitable for the study of ultra-wide spectrum of biological tissue, but the substrate material is usually needed for spectral measurement of biological tissue. The optical parameters of four typical substrate materials (quartz, high density polyethylene (HDPE), polytetrafluoroethylene (PTFE) and paraffin wax) were measured by terahertz ABCD system, and their absorption coefficients and refractive indices in the 1~15THz frequency range were calculated. The results show that high density polyethylene (HDPE) and paraffin wax can be used as substrate materials for ultra-wide band terahertz spectroscopy measurement of biological tissues. At the same time, although quartz and polytetrafluoroethylene are commonly used as substrates in narrow-band (0.1~3THz) terahertz systems, due to their strong absorption of terahertz waves in the frequency range higher than 5THz, Therefore, it can not be used as substrate material for ultra-wide band terahertz spectroscopy measurement.
【作者单位】：首都师范大学物理系;北京大学工学院;
【基金】：国家自然科学基金项目(11374007) 全国优秀博士论文项目(201237) 香江学者计划资助
【分类号】：O433

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