Light Diffraction by an Acoustic Surface Wave in Fused Quartz

Light diffraction by an acoustic surface strain wave in fused quartz was observed in the Debye-Sears limit. An acoustic surface wave has both compressional and shear strains. It is possible to observe and distinguish the diffraction of light caused by the two different strains since the diffracted beam polarization due to the shear strain is rotated 90° from the incident polarization. In the experiment performed 2.5% of the incident energy was diffracted into a single order. Light diffracted by both the compressional and shear strains was clearly identified.