Photoelastic characterization of ZnO films

The acoustooptic interaction between a light beam and acoustic modes propagating along a ZnO film, deposited on a AlzO3 substrate, has been exploited for analysing the photoeleastic prop erties of the film itself. The method relies on measurement of the intensity of the light scattered into the first diffraction order by different acoustic modes, for both s-and ppolarization of the incident light. Measurements performed on the first two acoustic modes supported by the film , enabled us to determine the photoelastic constants p11, plz and p13 of the ZnO film.