Surface-acoustic-wave guidance produced by ion implantation in quartz

An increase in the surface-acoustic-wave velocity is produced by ion implantation in quartz (y-cut, x-propagating). A 2.5% relative-velocity increase has been measured at 395 MHz, with 100 keV Li+ ions, the flux being 1016 ions/cm2. Slot acoustic waveguides have been realised at about 100 and 400 MHz by these techniques. Horns were used for matching the launched acoustic beams to the guides. An optical probe has been employed for investigating the spatial distribution of the acoustic power. The 100 MHz guide is 148 ¿m wide. The guided-power profile along a section of the guide has been measured. The 6 dB beamwidth is about 230 ¿m. The 400 MHz guide is 18 ¿m wide, and the propagation loss is about 0.75 dB/¿s.