Terahertz Techniques in NDE

So far, terahertz measurement technology has rarely been used in industry. This book chapter presents therefore the underlying technologies, the resulting possibilities and exemplary applications. The introduction describes the basic properties of terahertz systems and the advantages of terahertz technology over established techniques such as infrared, X-rays and ultrasound. The two industrially relevant terahertz techniques, time domain spectrometer and FMCW system, are described in detail. In addition, the metrological basics for their main applications are introduced. Imaging is required in many applications. Different approaches are presented. Before the chapter concludes with an outlook on future applications, current application examples are discussed. This concerns appli cations in the fields of coating thickness measurement, safety, materials research, testing of lightweight materials and inline testing. An extensive reference list provides a deeper insight into the topics addressed.