Abstract

The global increase of plastic production has led to an increase in coating materials available for plastics, as many plastics need to be protected from environmental factors such as light, solvents and other chemicals. For this reason the coating of plastics is a useful example for the coating thickness measurement on non-metal surfaces. Analogies can also be found in many other areas such as the wood and building industry. Terahertz (THz) waves penetrate nonconductive coatings and are reflected at the boundary layers between different refraction indices. This creates new potential for quality control when added to the already established nondestructive testing techniques such as ultrasonic or x-ray.

© 2011 Optical Society of America