Plasmonic acousto-optic transducer for high frequency surface acoustic waves

Acousto-Optic Transducers can be used for remote non-destructive testing in difficult to reach locations. These transducers can be activated with laser light and the reflected light can be detected with a remote receiver. Using fibers to transmit light to hard to reach locations, or attaching fibers to the proximity of the area under investigation can facilitate the extraction of data from such areas, when there is no line of sight available. In this article, the operating mechanism of a plasmonic-acousto-optic transducer, designed to be used with fiber optics, in order to detect very high frequency (~10GHz) surface acoustic waves is described. The displacement caused by the SAW modulates the coupling efficiency of the surface plasmon to the transducer, thus changing the reflection coefficient.