4.1 - Sensitive Determination of Layer Thickness by Waveguide Terahertz Time-Domain Spectroscopy

M. Theuer, D. Grischkowsky & R. Beigang
Thin film sensing and layer thickness determination are important for various industrial processes. The terahertz (THz) frequency band (located between 100 GHz and 10 THz, corresponding to wavelengths between 3000 μm and 30 μm in free-space) efficiently penetrates most dielectrics. Thus, THz non-destructive testing can be used to measure the thickness of common plastics and paint layers by evaluation of pulse delay information. We demonstrate the determination of layer thickness on dielectrically coated metal cylinders...