A novel time domain picosecond pulse sampling system for noncontact characterization of liquids, semiconductors, and metals

We firstly introduce a novel picosecond pulse sampling system with pulse beam paths in which the pulse is incident normally to the surface of the material under test. The newly designed beam path was possible using a quartz beam splitter for the picosecond electromagnetic pulse. The quartz was usually used for the beam splitter in the optical spectrum region. The quartz substrate has low attenuation and relatively uniform dielectric constant versus frequency in GHz range. To demonstrate the advantages of the proposed system, the dielectric constant and absorption coefficient of pure water was measured at the frequency range from 10 GHz to 100 GHz. The pulse beam is not only a nondestructive but also a noncontact method. Also, as the beam is normally incident to the surface, any semiconductors and metals can be easily tested as far as the materials are placed on the bottom of the system. The measurement results agree with the previous works, demonstrating the precision and the compactness of the measurement procedure.