A system for determining a material property at an interface between a first layer and a second layer includes a transmitter outputting electromagnetic radiation to the sample, a receiver receiving electromagnetic radiation that was reflected by or transmitted though the sample, and a data acquisition device. The data acquisition device digitizes the electromagnetic radiation to yield waveform data. The waveform data represents the radiation reflected by or transmitted though the sample. The material property to be determined is generally the adhesive strength between the first and second layers.