特种工程塑料太赫兹光学参数测量及误差分析

以聚苯硫醚(PPS)、聚醚酰亚胺(PEI)及其玻璃纤维增强材料(PPS-GF30，PEI-GF30)为样品，获得了在太赫兹频段的光谱特性。首先，利用太赫兹时域光谱系统，在透射模式下，测试了四种材料在自由空间的时域信号。然后，根据提取光学参数的物理模型及菲涅尔透射公式计算材料的折射率及消光系数，同时对物理模型和菲涅耳公式解析法仿真，保障了实验测试和算法的合理性与可靠性。最后，依据误差传输理论计算了由主要因素决定的光学参数误差。在样品各自的太赫兹有效频段，实验显示： PPS： n=1.889~1.945(误差0.003~0.012)，κ=0.001~0.047、(误差0.000 1~0.002 6)，PPS-GF30： n=1.654~1.672(误差0.003~0.004)，κ=0.002~0.057(误差0.000 1~0.002 8)，PEI： n=1.713~1.733(误差0.002~0.012)，κ=0.005~0.035(误差0.000 1~0.003 0)，PEI-GF30： n=1.688~1.732(误差0.003~0.004)，κ=0.036~0.068(误差0.000 2~0.002 6)。结果表明： 作为太赫兹超材料器件的基底，PPS适合低频，PEI适合高频，玻璃纤维增强的PPS，PEI相比纯样品，不仅力学性能得到改善，并有利于信号探测，而且在有效频段的高频部分，探测灵敏度更强。研究提供了PPS，PEI及其玻璃纤维增强材料在太赫兹频段的基础参数，为太赫兹领域超材料器件的研究提供了重要参考。

Terahertz Optical Parameters Measurement and Error Analysis of Special Engineering Plastic

Spectral characteristics are obtained for Polyphenylene sulfide (PPS), Polyetherimide (PEI) and glass-fiber reinforced composites. First, by using terahertz time-domain spectroscopy system, time-domain signal of four samples are detected in free space for transmission mode. Then, according to the physical model and Fresnel formula extracting optical parameters, refractive index and extinction coefficient are calculated. Meanwhile, simulation analysis ensures the rationality and reliability of the test and calculation. Finally, based on the theory of error diffusion, error caused by crucial factors is exactly computed. Experiments show that in samples’ respective terahertz effective spectrum, PPS’s optical constants appear at n=1.889~1.945 (error=0.003~0.012), κ=0.001~0.047 (error=0.000 1~0.002 6); PPS-GF30’s optical constants appear at n=1.654~1.672 (error=0.003~0.004), κ=0.001~0.047 (error=0.000 1~0.002 8); PEI’s optical constants appear at n=1.713~1.733 (error=0.002~0.012), κ=0.005~0.035 (error=0.000 1~0.003 0); PEI-GF30’s optical constants appear at n=1.688~1.732 (error=0.003~0.004), κ=0.036~0.068 (error=0.000 2~0.002 6). The results indicate that, as a base of terahertz meta-material device, PPS is suitable for low frequency, but PEI is just the opposite. Compared with the pure samples, glass fiber reinforced PPS and PEI have been improved not only in mechanical properties but also in signal detection. In addition, detection sensitivity is stronger in the high frequency range. The study provides basic optical parameters of PPS, PEI and glass fiber reinforced materials, and it is also an important reference for meta-material device research in terahertz field.