Study of Models on the Generation and Propagation of Photoacoustic Signals in a Drilled Hole in Epoxy Resin

Abstract

This paper describes improved models derived from an experiment in generation and propagation of photoacoustic signals in a drilled hole of an epoxy resin with different backing materials, a white polypropylene and a black one. The major difference between the improved and the old models is as follows. The photoacoustic signal at the top edge of the hole was generated not only due to absorbed incident light, but also due to absorbed and scattered light at the top edge of the hole. In addition, we show the propagation paths of the PA signals generated at the top edge of the hole.

Thermal diffusivities of commercial transparent polymer films measured using laser induced thermal wave

“…In 1986, we began to develop a compact scanning photoacoustic microscope (hereafter called SPAM) [4,5]. Up to now, defects in epoxy resin, the inner hole of the black carbon, and epoxy adhesive film have been successfully detected using our SPAM [6][7][8]. Recently, much of the attention of the industrial and academic fields has been shifting from the characterization of solid material, such as a ceramic or a single crystal, to that of transparent films such as those of SiO 2 , TiO 2 , and poly(vinylidene fluoride) (PVDF).…”