Non-invasive characterization of carbon fiber reinforced polymer composites using continuous wave terahertz system

THz Continuous Wave (CW) spectroscopy, both in transmission and reflection mode, is used for determining the attenuation coefficient and refractive index of Carbon Fiber Reinforced Polymer (CFRP) composites. Using CW transmission mode, attenuation coefficient of the CFRP sample has been calculated while the reflection mode setup has been used to calculate the refractive index of the sample. From the refractive index values, thickness of the CFRP sample has been calculated and has been compared with the measured thickness demonstrating the potential of THz spectroscopy to non-invasively characterize CFRP materials. In future, the attenuation coefficient information can be used to characterize the defects, contaminants, non-uniformities etc. in CFRP materials.