TY - CONF A1 - Spranger, Holger A1 - Beckmann, Jörg T1 - THz – ToF optical layer analysis (OLA) to determine optical properties of dielectric materials N2 - Electromagnetic waves with frequencies between 0.1 and 10 THz are described as THz-radiation (T-ray). The ability to penetrate dielectric materials makes T-rays attractive to reveal discontinuities in polymer and ceramic materials. THz-Time Domain Spectroscopy Systems (THz-TDS) are available on the market today which operates with THz-pulses transmitted and received by optically pumped semiconductor antennas. In THz-TDS the travelling time (ToF) and shape of the pulse is changed if it interacts with the dielectric material and its inherent discontinuities. A tomogram of the object under the test can be reconstructed from time of flight diffraction (ToFD) scans if a synthetic focusing aperture (SAFT) algorithm is applied. The knowledge of the base materials shape and optical properties is essential for a proper reconstruction result. To obtain these properties a model is assumed which describes the device under the test as multilayer structure composed of thin layers with different dielectric characteristics. The Optical Layer Analysis (OLA) is able to fulfill these requirements. A short description why the optical properties are crucial for meaningful SAFT reconstruction results will be given first. Afterwards the OLA will be derived and applied on representative samples to discuss and evaluate ist benefits and limits. T2 - QNDE 2016 CY - Atlanta, GA, USA DA - 17.07.2016 KW - Optical layer analysis KW - THz-TDS KW - Optical properties of dielectric materials KW - THz-ToF PY - 2017 SN - 978-0-7354-1474-7 U6 - https://doi.org/10.1063/1.4974707 SN - 0094-243X VL - 1806 IS - 1 SP - UNSP 120002, 1 EP - 7 PB - AIP Publishing AN - OPUS4-39393 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -