Learning Forum

[jie li]

Thank you for your answer.

1、I learned that the PTFE thickness is in the millimeter level, is a single substance, there is no SiO2.
2、In my eyes, PTFE is an insulator, should be regarded as a pure dielectric, I did not see in the paper there is a imaginary part of its refractive index (in terahertz band，refractive index of about 1.4, dielectric constant of about 2) (I am not familiar with this knowledge, please forgive my wrong expression).
3、What bothers me is that PTFE is pure white and SiO2 (quartz glass) is transparent in real life, but their refractive indices are close (resulting in the reflectivity calculated by me using Fresnel's formula is also close).
I wonder if my material model was applied incorrectly, or if the FDTD method is not suitable for simulation。